Vulnerability Description
Memory safety bugs present in 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 of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149.0.2 and Thunderbird 149.0.2.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 149.0.2 |
| Mozilla | Thunderbird | < 149.0.2 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025475%2C2025477Broken LinkIssue Tracking
- https://www.mozilla.org/security/advisories/mfsa2026-25/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-28/
FAQ
What is CVE-2026-5735?
CVE-2026-5735 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Memory safety bugs present in 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 of these could have been expl...
How severe is CVE-2026-5735?
CVE-2026-5735 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-5735?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.