CVE-2026-8974
Description
Memory safety bugs present in Firefox ESR 140.10 and Firefox 150. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-8974.html
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-8974
Vendor advisory: security@mozilla.org — https://www.mozilla.org/security/advisories/mfsa2026-51/
Vendor advisory: security@mozilla.org — https://www.mozilla.org/security/advisories/mfsa2026-50/
Vendor advisory: security@mozilla.org — https://www.mozilla.org/security/advisories/mfsa2026-48/
Vendor advisory: security@mozilla.org — https://www.mozilla.org/security/advisories/mfsa2026-46/
Vendor advisory: redhat — https://access.redhat.com/errata/RHSA-2026:21381
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| rhel | 9 | fixed | |
| debian | sid | fixed | 151.0-1 |
| debian | bookworm | fixed | 140.11.0esr-1~deb12u1 |
| debian | bullseye | fixed | 140.11.0esr-1~deb11u1 |
| debian | forky | fixed | 140.11.0esr-1 |
| debian | trixie | fixed | 140.11.0esr-1~deb13u1 |
| sles | affected | |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| mozilla | firefox | {"endExcluding":"140.11.0"} | 140.11.0 |
| mozilla | thunderbird | {"endExcluding":"140.11"} | 140.11 |
References
- https://access.redhat.com/errata/RHSA-2026:21381
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1784128%2C1883230%2C1983677%2C2022390%2C2023116%2C2023657%2C2024255%2C2024418%2C2024441%2C2024447%2C2024966%2C2025412%2C2025467%2C2025940%2C2025950%2C2025956%2C2026284%2C2027247%2C2027255%2C2027288%2C2027306%2C2027322%2C2027332%2C2027333%2C2028266%2C2028292%2C2028319%2C2028526%2C2028870%2C2028876%2C2028882%2C2029062%2C2029309%2C2029414%2C2029422%2C2029428%2C2029447%2C2029732%2C2029785%2C2029793%2C2029813%2C2029899%2C2031028%2C2031457%2C2032039%2C2033610%2C2033854%2C2034498%2C2034628%2C2034978%2C2035966%2C2036668%2C2036905%2C2036930
- https://www.mozilla.org/security/advisories/mfsa2026-46/
- https://www.mozilla.org/security/advisories/mfsa2026-48/
- https://www.mozilla.org/security/advisories/mfsa2026-50/
- https://www.mozilla.org/security/advisories/mfsa2026-51/
- https://security-tracker.debian.org/tracker/CVE-2026-8974
- https://www.suse.com/security/cve/CVE-2026-8974.html
CWEs
CWE-119
Verify integrity in audit chain (admin only). AS-IS.