Memory safety bugs fixed in Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141 and Thunderbird 141
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-119 and the CVSS impact.
Summary
Memory safety bugs present in Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Firefox | — | 140.1, 141 | Patch available | CNA |
| Mozilla | Thunderbird | — | 140.1, 141 | Patch available | CNA |
- Firefox VendorMozilla Affected — Fixed in 140.1, 141 Patch available CNA
- Thunderbird VendorMozilla Affected — Fixed in 140.1, 141 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* | before 140.1 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* | before 141.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* | before 140.1 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* | before 141.0 | Vulnerable | Mozilla |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* Versions before 140.1 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* Versions before 141.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* Versions before 140.1 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* Versions before 141.0 Vulnerable ·Mozilla
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 140.1, 141
- Fix · CNA Thunderbird (Mozilla) Fixed in 140.1, 141
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2025-8040
- 2026-10-03 Alias added: GHSA-7jcf-w576-jvj3
References
Advisory 4
More Mozilla Firefox vulnerabilities
- TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
- TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
- TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
- TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2025-8040 · CVE Program
- CVE-2025-8040 · NVD
- FIRST EPSS
- GHSA-7jcf-w576-jvj3 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-8040 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences