*3.38 G/T AUEQ (2.97 G/T AU, 1.80 G/T AG, 0.29 % CU) OVER 22 M, 0.95 G/T AUEQ (0.80 G/T AU, 1.11 G/T AG, 0.10 % CU) OVER 129.05 M

MONTREAL, Sept. 17, 2026 (GLOBE NEWSWIRE) -- Troilus Mining Corp. (“Troilus” or the “Company”) (TSX: TLG; OTCQX: CHXMF; FSE: CM5), is pleased to announce the fourth batch of results from the Z87 optimization drill program at its Troilus Gold-Copper Project located in north-central Quebec, Canada. The results reported include nine drill holes totaling 4,728 metres, and form part of the 2026 exploration program outlined in the Company’s March 31, 2026 press release.

The ongoing Z87 optimization program is is targeting Inferred material and historically unsampled intervals within and around the current Z87 Reserve pit, with the objective of identifying opportunities to improve the mine plan presented in the Company’s Technical Report on September 9 ^th , 2026.

Importantly, the current Mineral Resource and Mineral Reserve estimates have an effective date of December 31, 2025, and therefore exclude all drilling completed in 2026. The results reported today continue to demonstrate mineralization in areas currently classified as Inferred or, in some cases, treated as waste in the existing block model, creating potential opportunities for resource conversion, pit and mining sequence optimization, strip ratio improvements and enhanced early-year mill feed.

Z87 Intercept Highlights:

Hole 87-26-485 intersected 0.95 g/t gold equivalent (“AuEq”) (0.80 g/t Au, 1.11 g/t Ag, 0.10% Cu) over 129.05 m, including 3.38 g/t AuEq (2.97g/t Au, 1.80 g/t Ag, 0.29 % Cu) over 22 m starting at 398 m downhole from an area of inferred material within the Z87 reserve pit (see Figures 1 and 2).
Hole 87-26-531 intersected 0.99 g/t gold equivalent (“AuEq”) (0.84 g/t Au, 1.20 g/t Ag, 0.10 % Cu) over 74.3 m, including 3.15 g/t AuEq (2.73 g/t Au, 1.88 g/t Ag, 0.30 % Cu) over 3.3m starting at 468 m downhole from an area of inferred material within the Z87 reserve pit (see Figures 1 and 2).
Hole 87-26-529 intersected 1.15 g/t gold equivalent (“AuEq”) (1.00 g/t Au, 0.84 g/t Ag, 0.11 % Cu) over 45 m, including 5.42 g/t AuEq (4.73 g/t Au, 5.45 g/t Ag, 0.46 % Cu) over 2 m starting at 579 m from an area of inferred material 70 m below the Z87 reserve pit(see Figures 1 and 3).
Hole 87-26-515 intersected several intervals of mineralization in the historically unsampled Z87 hangingwall where the current resource model does not contain mineralized blocks (see Figure 3 and Table 1).

Justin Reid, CEO of Troilus, commented, “None of our 2026 drilling is included in the latest Resource and Reserve estimates, and we continue to see impactful drill results from within and around the Z87 Reserve pit. We are targeting Inferred material and historically unsampled intervals, and the drilling is showing more extensive mineralization than is currently represented in the resource model. The results indicate mineralization in an area that is currently modeled as waste. Subject to further drilling, geological modelling, engineering evaluation and incorporation into future mine-plan updates, the mineralization may have the potential to reduce waste movement and improve strip ratios in this portion of the deposit.”.”

Z87 Optimization Program

Z87 was one of two zones previously mined by open pit during the former Troilus operation. Many of the historical drill holes used to define the former mine reserve were not continuously sampled, leaving intervals of core - in some cases extending for several hundred metres - without assay data.

For the purposes of resource estimation, these unsampled intervals are assigned values equal to one-half of the laboratory detection limit, resulting in significant gaps within the current block model. The 2026 optimization program is systematically testing these areas to determine whether mineralization extends through historically unsampled intervals that are presently modelled as waste.

The program is also targeting Inferred material within and around the current Z87 Reserve pit, with the objective of collecting data to support potential conversion to the Indicated category and consideration for possible incorporation into future Mineral Reserve and mine-plan updates.

The results announced today build on earlier 2026 drilling at Z87 that has demonstrated mineralization beyond and within the current Reserve pit, including broad intervals encountered in historically unsampled areas of the hangingwall (see press releases dated August 20, 2026, July 7, 2026 and June 25, 2026.)

All grades are uncut, and true thicknesses are approximately 75% to 90% of drilled length.

*The NI 43-101 technical report associated with the mineral Resources and Reserves of the Troilus Project can be found on SEDAR+ at www.sedarplus.ca under the Company’s issuer profile or on the Company’s website at www.troilusmining.com

260917_TLG_Fig 1

Figure 1. Plan map with the reported drill hole locations from Z87

Figure 2. Cross section showing results for drillhole 87-26-485 and 87-26-531.

Figure 3. Cross section showing results for drillhole 87-26-515 and 87-26-529.

Z87 Drilling

Dillholes 87-26-485 was drilled to target inferred material within the Z87 reserve pit (see Figures 1 and 2). The main zone returned 129.05 metres grading 0.95 g/t AuEq including 3.38 g/t AuEq over 22 metres, which includes 4.34 g/t AuEq over 12.47 metres. This area of the reserve pit contains inferred blocks that are not incorporated into the current mine plan. This drilling was planned with the goal of upgrading the resource to the Indicated category for consideration in future production schedules.

On the same section, 120 metres down dip, drillhole 87-26-531 returned 125.5 metres grading 0.74 g/t AuEq, including 74.3 metres grading 0.99 g/t AuEq from the main zone of Z87, where it was targeting Inferred material. The hangingwall returned 20 metres grading 0.31 g/t AuEq and 41.4 metres grading 0.28 g/t AuEq where the current block model does not contain mineralization, as this area is informed by historically unsampled drillholes.

On a section 50m south of 87-26-485 and 87-26 531 (Figure 1), drillhole 87-26-529 returned 1.15 g/t AuEq over 45 metres within a broader zone of 0.51 g/t AuEq over 154 metres from the main zone of Z87 approximately 70 metres below the reserve pit (see Figure 3). This hole also returned 73 metres grading 0.35 g/t AuEq including 0.72 g/t AuEq over 13 metres from the Z87 hangingwall and 0.53 g/t AuEq over 40 metres including 1.54 g/t AuEq over 8 metres from the footwall. These intercepts present significantly broader mineralization than is currently in the resource model.

87-26-515 was drilled to target an area of historically unsampled material approximately 50 metres up dip of hole 87-26-529. This hole returned several intervals of mineralization where the current resource is unmineralized due to the impacts of historically unsampled intervals being assigned half the lab analysis detection limit for the purpose of resource estimation. These intercepts include 0.80 g/t AuEq over 8 metres including 1.48 g/t AuEq over 3 metres, 0.61 g/t AuEq over 12 metres including 1.52 g/t AuEq over 3.5 metres, 1.15 g/t AuEq over 7 metres including 5.04 g/t AuEq over 1 metres and 93 metres grading 0.46 g/t AuEq, which including intercepts of 1.07 g/t AuEq over 10 metres and 1.06 g/t AuEq over 10 metres.

To date, Troilus has released 39 drillholes totaling 14,521 metres of the approximately 24,000 metres allocated to the Z87 pit optimization program, which includes the targeting of Inferred and unsampled material within and around the reserve pit shell.

Table 1. Z87 Drill Results

Hole	From (m)	To (m)	Interval (m)	Au Grade (g/t)	Cu Grade (%)	Ag Grade (g/t)	AuEq Grade (g/t)
87-26-485(-47° dip)
	63	81	18	0.40	0.01	0.70	0.42
incl	68	69.38	1.38	2.95	0.04	5.00	3.07
	173.5	175	1.5	0.75	0.01	0.50	0.77
	214	221	7	0.20	0.02	0.38	0.23
	233	237	4	0.39	0.03	0.31	0.44
	257.77	273	15.23	0.22	0.03	0.47	0.27
	348	390	42	0.31	0.02	0.32	0.33
	398	527.05	129.05	0.80	0.10	1.11	0.95
incl	449	471	22	2.97	0.29	1.80	3.38
incl	456.18	468.65	12.47	3.91	0.30	1.82	4.34
incl	500	501	1	2.70	0.37	4.40	3.26
	533	563	30	0.61	0.05	1.15	0.69
incl	540	545	5	1.48	0.13	4.08	1.72
incl	543	544	1	2.99	0.21	8.10	3.38
	569	598	29	0.21	0.03	0.53	0.25
87-26-511(-51° dip)
	24	26	2	0.69	0.01	0.25	0.71
	34	51	17	0.43	0.01	0.34	0.45
incl	46	47	1	2.02	0.00	0.25	2.03
	58	67	9	0.17	0.02	0.35	0.21
	80	94	14	0.22	0.00	0.25	0.22
	115.5	117.5	2	0.65	0.00	0.25	0.66
	180	188	8	0.34	0.03	0.47	0.39
	236	240	4	0.52	0.00	0.25	0.53
87-26-515(-62° dip)
	32	38	6	0.28	0.01	0.25	0.30
	50.45	56	5.55	0.80	0.03	1.38	0.86
incl	50.45	51.36	0.91	3.75	0.06	3.00	3.87
	67	73	6	0.24	0.01	0.25	0.25
	98	105	7	1.52	0.01	0.71	1.55
incl	104	105	1	9.57	0.08	3.50	9.73
	141	149	8	0.77	0.02	0.51	0.80
incl	143	146	3	1.48	0.05	0.95	1.55
	190	194	4	0.50	0.00	0.25	0.51
	285	292	7	0.29	0.00	0.25	0.30
	299	324	25	0.22	0.01	0.54	0.24
	350	362.5	12.5	0.45	0.03	1.11	0.50
incl	362	362.5	0.5	7.08	0.00	0.25	7.09
	371	383	12	0.58	0.02	0.60	0.61
incl	371	374.5	3.5	1.49	0.02	0.86	1.52
incl	371	372	1	3.94	0.01	0.25	3.96
	388.5	396	7.5	0.22	0.01	0.25	0.23
	405	412	7	1.11	0.03	0.35	1.15
incl	406	407	1	4.98	0.04	0.70	5.04
	423	516	93	0.42	0.02	0.33	0.46
incl	447	457	10	0.96	0.07	0.69	1.07
incl	447	448	1	5.19	0.07	0.70	5.30
incl	456	457	1	1.77	0.31	2.10	2.21
incl	489	499	10	1.01	0.03	0.38	1.06
incl	490	491	1	3.79	0.08	1.50	3.92
87-26-529(-60° dip)
	130	148.15	18.15	0.47	0.02	0.76	0.52
incl	146	147	1	2.94	0.16	5.40	3.23
	205	209	4	0.34	0.00	0.25	0.34
	219	236	17	0.41	0.01	0.25	0.43
	245	250	5	0.22	0.00	0.25	0.22
	322.4	323	0.6	2.20	0.02	4.30	2.29
	382	455	73	0.31	0.02	0.51	0.35
incl	387	388	1	3.47	0.30	9.60	3.99
incl	424	437	13	0.64	0.06	0.78	0.72
	462	472	10	0.37	0.01	0.25	0.38
	480	487	7	0.22	0.01	0.30	0.24
	513	667	154	0.43	0.05	0.56	0.51
incl	579	624	45	1.00	0.11	0.84	1.15
incl	598	611	13	1.68	0.16	1.38	1.92
incl	598	600	2	4.73	0.46	5.45	5.42
incl	599	600	1	7.34	0.44	7.40	8.02
incl	610	611	1	5.81	0.09	1.10	5.94
	674	714	40	0.45	0.05	1.36	0.53
incl	688	696	8	1.41	0.08	1.23	1.54
incl	691	692	1	6.75	0.19	3.30	7.05
87-26-531(-60° dip)
	15	24	9	0.52	0.01	1.96	0.56
incl	15	16	1	2.32	0.01	3.10	2.38
	47	51	4	0.27	0.00	0.25	0.28
	71	82	11	0.30	0.00	0.31	0.31
	108	116	8	0.21	0.01	0.52	0.22
	251	251.5	0.5	2.07	0.00	4.90	2.14
	272	292	20	0.29	0.01	0.27	0.31
	313	354.4	41.4	0.26	0.01	0.54	0.28
	404	415	11	0.20	0.01	0.30	0.22
	423	548.5	125.5	0.64	0.07	0.95	0.74
incl	440	446	6	0.92	0.07	0.65	1.02
incl	468	542.3	74.3	0.84	0.10	1.20	0.99
incl	491	499.3	8.3	1.83	0.17	1.96	2.09
incl	496	499.3	3.3	2.73	0.30	1.88	3.15
incl	516	517	1	3.69	0.00	0.25	3.70
	560	586.5	26.5	0.44	0.06	1.45	0.54
incl	570	572	2	2.20	0.35	5.30	2.74
87-26-532(-64° dip)
	43	65	22	1.44	0.01	0.55	1.47
incl	48	61	13	2.25	0.01	0.61	2.27
incl	48	51	3	5.35	0.00	0.25	5.36
	122	125	3	0.43	0.00	0.25	0.44
	141	142	1	1.38	0.06	0.50	1.47
	240	242	2	3.68	0.01	1.05	3.70
	281	289	8	0.49	0.00	0.25	0.49
	350	377	27	0.36	0.01	0.34	0.38
incl	350	353	3	1.04	0.05	0.68	1.12
	393	408	15	0.49	0.03	0.32	0.53
incl	393	394	1	2.87	0.01	0.25	2.89
	439	457	18	1.66	0.02	0.27	1.69
incl	442	443	1	26.50	0.02	0.60	26.53
	464	542	78	0.64	0.09	1.04	0.78
incl	465	473	8	2.03	0.32	3.17	2.50
incl	468	473	5	2.64	0.42	4.42	3.26
incl	493	506	13	0.92	0.09	0.73	1.05
	564	566	2	0.94	0.03	0.53	0.99
	576	600	24	0.42	0.02	0.88	0.47
incl	591	592	1	2.74	0.02	2.70	2.80
incl	599	600	1	2.76	0.01	0.70	2.79
87-26-534(-53° dip)
	105	113	8	0.18	0.01	0.25	0.20
	140	154	14	0.33	0.01	0.28	0.34
incl	147	148	1	1.74	0.04	0.70	1.80
	185	210.6	25.6	0.47	0.01	0.27	0.48
incl	192	197	5	1.28	0.02	0.25	1.31
incl	208	208.5	0.5	3.95	0.00	0.25	3.96
	218	225	7	0.65	0.04	0.46	0.72
incl	223	224	1	2.66	0.03	0.25	2.70
	240	250	10	2.92	0.07	0.69	3.02
incl	242	243	1	2.32	0.00	0.25	2.33
incl	249	250	1	24.30	0.21	1.20	24.59
	269	270	1	1.08	0.01	0.25	1.09
	305	310	5	0.21	0.01	0.25	0.22
	317	330	13	0.46	0.03	0.31	0.50
	336	359	23	0.99	0.05	0.70	1.07
incl	339	340	1	3.57	0.06	3.10	3.69
incl	347	349	2	2.06	0.14	1.15	2.26
incl	356	358	2	5.23	0.19	2.35	5.52
	365	400	35	0.65	0.04	0.41	0.71
incl	371	390.9	19.9	0.91	0.05	0.50	0.99
incl	371	381	10	1.62	0.05	0.58	1.69
incl	380	381	1	7.66	0.03	0.50	7.71
	406	434	28	0.16	0.06	0.61	0.25
	450	471	21	0.92	0.04	0.86	0.98
incl	450	451	1	10.05	0.16	3.50	10.31
incl	459	460	1	2.37	0.09	1.10	2.50
	484	497	13	0.17	0.03	0.41	0.22
87-26-544(-55° dip)
	144	157	13	0.17	0.02	0.28	0.20
	160	164.5	4.5	0.20	0.03	0.34	0.25
	187.2	194.5	7.3	0.35	0.06	0.63	0.44
	222	225	3	1.48	0.06	2.23	1.59
	248	275	27	0.21	0.01	0.40	0.23
	282	286	4	0.37	0.03	0.54	0.42
	292	302	10	0.23	0.03	0.53	0.27
	309	314	5	0.84	0.03	0.54	0.88
incl	313	314	1	2.16	0.03	1.10	2.21
	332	336	4	0.21	0.05	0.60	0.28
	345	366	21	0.20	0.05	1.19	0.28
87-26-545(-55° dip)
	120	124	4	0.67	0.01	0.25	0.69
incl	122	123	1	1.61	0.01	0.25	1.62
	155	161	6	0.64	0.08	3.24	0.79
incl	157	158	1	2.30	0.16	10.50	2.66
	180	185	5	0.20	0.01	0.49	0.23
	245	254	9	0.49	0.01	0.28	0.51
incl	253	254	1	3.30	0.01	0.50	3.33
	286	299	13	0.22	0.05	0.42	0.30
	318	328	10	1.84	0.12	0.63	2.01
incl	318	322	4	4.21	0.22	1.01	4.51
incl	321	322	1	12.05	0.07	0.50	12.15
	334	348	14	0.30	0.09	0.72	0.44
	354	361	7	0.48	0.05	0.49	0.56
	367	396	29	0.46	0.02	0.69	0.50
incl	376	380	4	1.33	0.01	0.25	1.36
incl	376	377	1	3.19	0.01	0.25	3.20
	419	425	6	0.33	0.07	1.36	0.44
	435	436	1	3.22	0.00	0.50	3.23
incl	419	420	1	1.26	0.22	4.30	1.61

^{* AuEq = Au grade + 1.3365 * Cu grade + 0.0136 * Ag grade}

Quality Assurance and Control

During the drill program, one meter assay samples were taken from NQ core and sawed in half. One-half was sent for assaying at ALS Laboratory in Sudbury Ontario, a certified independent commercial laboratory, and the other half was retained for results, cross checks, and future reference. A strict QA/QC program was applied to all samples; which included insertion of one certified mineralized standard and one blank sample in each batch of 25 samples. Every sample was processed with standard crushing to 85% passing 75 microns on 500 g splits. Samples were assayed by one-AT (30 g) fire assay with an AA finish and if results were higher than 3.5 g/t Au, assays were redone with a gravimetric finish. For QA/QC samples, a 50 g fire assay was done. In addition to gold, ALS laboratory carried out multi-element analysis for ME-ICP61 analysis of 33 elements four acid ICP-AES.

Qualified Person

The technical and scientific information in this press release has been reviewed and approved by Nicolas Guest, P.Geo., Exploration Manager, who is a Qualified Person as defined by NI 43-101. Mr. Guest is an employee of Troilus and is not independent of the Company under NI 43-101.

AuEq Disclosure

The formulas used to calculate equivalent values for resources are as follows, for 87 Pit AuEq = Au + 1.3365*Cu +0.0136 Ag, for J Pit AuEq = Au + 1.3618Cu +0.0137 Ag, for SW Pit AuEq = Au + 1.3856Cu +0.01141 Ag, for X22 Pit AuEq = Au + 1.3168Cu +0.0136 *Ag. AuEq was calculated using metal prices of $2,415/oz Au; $4.60/lb Cu and $32.00/oz Ag and recoveries of 84.5% for Au, 86.9% for Ag and 88.1% for Cu in the J pit, 85.9% for Au, 87.6% for Ag and 87.9% for Cu in the 87 pit, 82.1% for Au, 87.1% for Ag and 87.1% for Cu in the SW pit and 85.6 % for Au, 87.0% for Ag and 86.3% for Cu in the X22 pit.

About Troilus Mining Corp.

Troilus Mining Corp. is a Canadian development-stage mining company focused on the systematic advancement of the former gold and copper Troilus Mine towards production. Troilus is located in the tier-one mining jurisdiction of Quebec, Canada, where it holds a large land position of 435 km² in the Frôtet-Evans Greenstone Belt. A technical report completed in September 2026 supports a large-scale 26-year, 50ktpd open-pit mining operation, positioning it as a cornerstone project in North America.

For more information:

Caroline Arsenault
VP Corporate Communications
+1 (647) 276-0050
info@troilusmining.com

Cautionary Note Regarding Forward-Looking Statements and Information

This press release contains “forward-looking statements” within the meaning of applicable Canadian securities legislation. Forward-looking statements include, but are not limited to, statements regarding the impact of the drill results on the Company, the likelihood that the results will result in an improvement to the mine plan, the likelihood that mineralization in areas currently classified as Inferred will create potential opportunities for resource conversion, the results of the Technical Report, including, without limitation various project economics, financial and operational parameters such as the timing and amount of future production from the Project, expectations with respect to the IRR, NPV, payback and costs of the Project, anticipated mining and processing methods of the Project; proposed infrastructures, anticipated mine life of the Project, expected recoveries and grades, opportunity to expand the scale of the project, the project becoming a cornerstone mining project in Noth America; the development potential and timetable of the project; the estimation of mineral resources and reserves; realization of mineral resource and reserve estimates; the timing and amount of estimated future exploration; costs of future activities; capital and operating expenditures; success of exploration activities; the anticipated ability of investors to continue benefiting from the Company’s low discovery costs, technical expertise and support from local communities, the timing and amount of estimated future exploration; and the anticipated results of the Company’s 2026 drill program and their possible impact on the potential size of the mineral resource estimate. Generally, forward-looking statements can be identified by the use of forward-looking terminology such as “plans”, “expects” or “does not expect”, “is expected”, “budget”, “scheduled”, “estimates”, “forecasts”, “intends”, “continue”, “anticipates” or “does not anticipate”, or “believes”, or variations of such words and phrases or statements that certain actions, events or results “may”, “could”, “would”, “will”, “might” or “will be taken”, “occur” or “be achieved”.

Forward-looking statements are made based upon certain assumptions and other important facts that, if untrue, could cause the actual results, performances or achievements of Troilus to be materially different from future results, performances or achievements expressed or implied by such statements. Such statements and information are based on numerous assumptions regarding present and future business strategies and the environment in which Troilus will operate in the future. Certain important factors that could cause actual results, performances or achievements to differ materially from those in the forward-looking statements include, amongst others, currency fluctuations, the global economic climate, dilution, share price volatility and competition. Forward-looking statements are subject to known and unknown risks, uncertainties and other important factors that may cause the actual results, level of activity, performance or achievements of Troilus to be materially different from those expressed or implied by such forward-looking statements, including but not limited to: there being no assurance that the exploration program or programs of the Company will result in expanded mineral resources; risks and uncertainties inherent to mineral resource and reserve estimates; the high degree of uncertainties inherent to feasibility studies and other mining and economic studies which are based to a significant extent on various assumptions; variations in gold prices and other metals, exchange rate fluctuations; variations in cost of supplies and labour; receipt of necessary approvals; availability of financing for project development; uncertainties and risks with respect to developing mining projects; general business, economic, competitive, political and social uncertainties; future gold and other metal prices; accidents, labour disputes and shortages; environmental and other risks of the mining industry, including without limitation, risks and uncertainties discussed in the Company’s latest Annual Information Form, its technical reports and other continuous disclosure documents of the Company available under the Company’s profile at www.sedarplus.ca. Although Troilus has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements. Troilus does not undertake to update any forward-looking statements, except in accordance with applicable securities laws.

Photos accompanying this announcement are available at

https://www.globenewswire.com/NewsRoom/AttachmentNg/dee0a1c1-3e96-4fd7-bef4-396237e24508

https://www.globenewswire.com/NewsRoom/AttachmentNg/803a7ee1-e899-44f4-9cd8-8fac115290a9

https://www.globenewswire.com/NewsRoom/AttachmentNg/8d866bb1-4c22-4f4c-9625-c2d7dc7f4893

Troilus Drills 3.38 g/t AuEq Over 22 m Within 129.05 m at 0.95 g/t AuEq from Inferred Target in the Z87 Reserve Pit