Incorrect boundary conditions in Mozilla Firefox Layout component
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.
Summary
Incorrect boundary conditions in the Layout component of Mozilla Firefox and Thunderbird can break memory buffer bounds (CWE-119). An unauthenticated remote attacker can trigger it if a user interacts with crafted content, with low impact to confidentiality and integrity.
Written with Claude Haiku 5.5 from the sources below · 2026-10-27
Description from the CNA
Incorrect boundary conditions in the Layout component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
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 | — | 158 | Patch available | CNA |
| Mozilla | Thunderbird | — | 158 | Patch available | CNA |
Remediation
Update Mozilla Firefox and Thunderbird to version 158, which fixes this flaw.
Written with Claude Haiku 5.5 from the sources below · 2026-10-27
- Fix · CNA Firefox (Mozilla) Fixed in 158
- Fix · CNA Thunderbird (Mozilla) Fixed in 158
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
- 2026-10-13 Threatist record created from CVE-2026-109714
- 2026-10-13 Alias added: GHSA-h9v8-63qj-vhv8
- 2026-10-13 Fix available: Mozilla/Thunderbird@158 · CNA
- 2026-10-13 1 new reference · CNA
- 2026-10-16 CVSS score added · CISA ADP
- 2026-10-16 Weakness changed · CISA ADP
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-23 Affected versions changed · Red Hat
- 2026-10-23 CVSS score added · Red Hat
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-2026-109714 · CVE Program
- CVE-2026-109714 · NVD
- FIRST EPSS
- GHSA-h9v8-63qj-vhv8 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-109714 · 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