Vulnerability in Mozilla Firefox
CVE-2026-5731
Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some…
EPSS: 0.001 (21.8th percentile) — read the EPSS interpretation.
Affected products
- Mozilla Firefox — versions 115.34.1, 140.9.1, 149.0.2
- Mozilla Thunderbird — versions 140.9.1, 149.0.2
References
- Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2
- www.mozilla.org/security/advisories/mfsa2026-25/
- www.mozilla.org/security/advisories/mfsa2026-26/
- www.mozilla.org/security/advisories/mfsa2026-27/
- www.mozilla.org/security/advisories/mfsa2026-28/
- www.mozilla.org/security/advisories/mfsa2026-29/