Memory corruption in Mozilla Firefox
Priority LOW 37CWE-119Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Partial Red Hat: 4 fixed, 4 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-119 and the CVSS impact.
Summary
Incorrect boundary conditions in the Layout component. This vulnerability was fixed in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00343 27th percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 115.43, 153.5, 158Thunderbird (Mozilla): 153.5, 158Red Hat: 5 advisoriesRed Hat: 4 fixed, 4 without a fix
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 | — | 115.43, 153.5, 158 | Patch available | CNA |
| Mozilla | Thunderbird | — | 153.5, 158 | Patch available | CNA |
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 115.43, 153.5, 158
- Fix · CNA Thunderbird (Mozilla) Fixed in 153.5, 158
Red Hat 5 advisories
- RHSA-2026:95596 Released 2026-11-05 · Red Hat rating Importantthunderbird security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-153.5.0-1.el9_6
- RHSA-2026:95597 Released 2026-11-05 · Red Hat rating Importantthunderbird security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) thunderbird-153.5.0-1.el9_4
- RHSA-2026:93443 Released 2026-11-02 · Red Hat rating Importantthunderbird security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) thunderbird-153.5.0-1.el9_8
Show 2 more Red Hat advisories
- RHSA-2026:89757 Released 2026-10-26 · Red Hat rating Importantfirefox security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) firefox-153.5.0-1.el9_8, firefox-x11-153.5.0-1.el9_8
- RHSA-2026:89756 Released 2026-10-26 · Red Hat rating Importantfirefox security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-153.5.0-1.el8_10
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:89756 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:89757, RHSA-2026:93443 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:95597 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:95596 |
Timeline
- 2026-10-13 Threatist record created from CVE-2026-109753
- 2026-10-13 Alias added: GHSA-qrr3-f9g6-cf9g
- 2026-10-13 Fix available: Mozilla/[email protected], Mozilla/Thunderbird@158 · CNA
- 2026-10-13 2 new references · CNA
- 2026-10-16 CVSS score added · CISA ADP
- 2026-10-16 Weakness changed · CISA ADP
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-31 Affected versions changed · Red Hat
- 2026-10-31 CVSS score added · Red Hat
- 2026-10-31 Fix available: RHSA-2026:89757 · Red Hat
- 2026-10-31 Fix available: RHSA-2026:89756 · Red Hat
- 2026-10-31 Fix available: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux AppStream (v. 9) · Red Hat
- 2026-11-02 Fix available: RHSA-2026:93443 · Red Hat
- 2026-11-02 Affected versions changed · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95597 · Red Hat
- 2026-11-06 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux AppStream EUS (v.9.6) · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95596 · Red Hat
References
Other 6
- https://bugzilla.mozilla.org/show_bug.cgi?id=2068441
- https://www.mozilla.org/security/advisories/mfsa2026-106/
- https://www.mozilla.org/security/advisories/mfsa2026-107/
- https://www.mozilla.org/security/advisories/mfsa2026-108/
- https://www.mozilla.org/security/advisories/mfsa2026-109/
- https://www.mozilla.org/security/advisories/mfsa2026-110/
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-2026-109753 · CVE Program
- CVE-2026-109753 · NVD
- FIRST EPSS
- GHSA-qrr3-f9g6-cf9g · GitHub Advisory Database · CC BY 4.0
- CVE-2026-109753 · 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