CVE-2026-2781
CRITICALCVSS 9.8/10EPSS 0.36%
Last modified
CVE-2026-2781 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Integer overflow in the Libraries component in NSS. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, Thunderbird 140.8, and Firefox ESR 115.35.. EPSS estimates a 0.36% chance of exploitation in the next 30 days.
Description
Integer overflow in the Libraries component in NSS. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, Thunderbird 140.8, and Firefox ESR 115.35.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 140.8.0 |
| Mozilla | Firefox | < 148.0 |
| Mozilla | Thunderbird | < 140.8.0 |
| Mozilla | Thunderbird | < 148.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2009552Issue Tracking, Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-13/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-15/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-16/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-17/Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2026-2781?
Integer overflow in the Libraries component in NSS. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, Thunderbird 140.8, and Firefox ESR 115.35.
How severe is CVE-2026-2781?
CVE-2026-2781 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.
How do I fix CVE-2026-2781?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
Are you affected by CVE-2026-2781?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST