Sandbox escape in Mozilla Firefox and Thunderbird Storage Quota Manager
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
Mozilla Firefox and Thunderbird contain a sandbox escape flaw in the Storage Quota Manager component caused by incorrect boundary conditions. The flaw matches CWE-119, where an operation goes outside the bounds of a memory buffer. An unauthenticated remote attacker can exploit it if a user interacts with crafted content, and a successful attack can affect confidentiality, integrity and availability. The source description does not report public exploitation.
Written with Claude Haiku 5.5 from the sources below · 2026-11-05
Description from the CNA
Sandbox escape due to incorrect boundary conditions in the Storage: Quota Manager component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
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 | — | 153.6, 159 | Patch available | CNA |
| Mozilla | Thunderbird | — | 153.6, 159 | Patch available | CNA |
Remediation
Update Firefox to version 153.6 or 159, and update Thunderbird to version 153.6 or 159. The sources do not name a separate advisory identifier for this fix.
Written with Claude Haiku 5.5 from the sources below · 2026-11-05
- Fix · CNA Firefox (Mozilla) Fixed in 153.6, 159
- Fix · CNA Thunderbird (Mozilla) Fixed in 153.6, 159
Timeline
- 2026-10-27 Threatist record created from CVE-2026-117962
- 2026-10-27 Fix available: Mozilla/Thunderbird@159 · CNA
- 2026-10-27 1 new reference · CNA
- 2026-10-27 Fix available: Mozilla/[email protected] · CNA
- 2026-10-27 1 new reference · CNA
- 2026-10-27 Alias added: GHSA-ccxr-hh79-x5c4
- 2026-11-05 CVSS score added · CISA ADP
- 2026-11-05 Weakness changed · CISA ADP
- 2026-11-05 CISA SSVC decision points changed
- 2026-11-05 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-2026-117962 · CVE Program
- CVE-2026-117962 · NVD
- FIRST EPSS
- GHSA-ccxr-hh79-x5c4 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences