CVE-2026-8956
Description
Integer overflow in the Networking: JAR component. 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-2026-8956.html
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-8956
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/show_bug.cgi?id=2032427
- 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-2026-8956
- https://www.suse.com/security/cve/CVE-2026-8956.html
CWEs
CWE-190
Verify integrity in audit chain (admin only). AS-IS.