Use-after-free in Firefox WebRTC signaling allows privilege escalation
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-416 and the CVSS impact.
Summary
Mozilla Firefox and Thunderbird are affected by a use-after-free in the WebRTC Signaling component (CWE-416). A remote attacker with no privileges can escalate privileges when a user takes an action. The flaw is rated high severity with a CVSS base score of 8.8.
Written with Claude Haiku 5.5 from the sources below · 2026-11-05
Description from the CNA
Privilege escalation due to use-after-free in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 159 and Thunderbird 159.
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 | — | 159 | Patch available | CNA |
| Mozilla | Thunderbird | — | 159 | Patch available | CNA |
Remediation
Mozilla Firefox and Thunderbird fixed this in version 159. Update Firefox to version 159 and Thunderbird to version 159 or later.
Written with Claude Haiku 5.5 from the sources below · 2026-11-05
- Fix · CNA Firefox (Mozilla) Fixed in 159
- Fix · CNA Thunderbird (Mozilla) Fixed in 159
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
- 2026-10-27 Threatist record created from CVE-2026-118006
- 2026-10-27 Fix available: Mozilla/Thunderbird@159 · CNA
- 2026-10-27 1 new reference · CNA
- 2026-10-27 Alias added: GHSA-6rm7-m7j3-jc8q
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 CVSS score added · Red Hat
- 2026-11-05 CVSS score added · CISA ADP
- 2026-11-05 Weakness changed · CISA ADP
- 2026-11-05 CISA SSVC decision points changed
- 2026-11-07 Priority changed: LOW → MEDIUM
References
More Mozilla 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-2026-118006 · CVE Program
- CVE-2026-118006 · NVD
- FIRST EPSS
- GHSA-6rm7-m7j3-jc8q · GitHub Advisory Database · CC BY 4.0
- CVE-2026-118006 · 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