Internally found bugs fixed in Firefox ESR 153.1 and Firefox 154
Priority MEDIUM 50CWE-119Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- 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
Internally found bugs present in Firefox ESR 153.0 and Firefox 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00609 49th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 153.1, 154Thunderbird (Mozilla): 153.1, 154
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- 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 | — | 153.1, 154 | Patch available | CNA |
| Mozilla | Thunderbird | — | 153.1, 154 | Patch available | CNA |
- Firefox VendorMozilla Affected — Fixed in 153.1, 154 Patch available CNA
- Thunderbird VendorMozilla Affected — Fixed in 153.1, 154 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 153.1.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* | before 153.1.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 153.1.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* | before 153.1.0 | Vulnerable | Mozilla |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 153.1.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* Versions before 153.1.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 153.1.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* Versions before 153.1.0 Vulnerable ·Mozilla
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 153.1, 154
- Fix · CNA Thunderbird (Mozilla) Fixed in 153.1, 154
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-2026-74988
- 2026-10-03 Alias added: GHSA-qmcg-gf85-vjv7
- 2026-10-28 Title updated · CNA
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-2026-74988 · CVE Program
- CVE-2026-74988 · NVD
- FIRST EPSS
- GHSA-qmcg-gf85-vjv7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-74988 · 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