High 8.8Published Feb 24, 2026

CVE-2026-2781Integer overflow in the Libraries component in NSS

Updated under an hour ago (Oct 27, 2026, 6:23 AM ET)

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It affects Mozilla Firefox and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Mozilla Firefox

Exploited in the last 30 days

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.

CVSS: 8.8 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-190
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: mozilla
NVD analysis: Modified
Record last updated: Apr 21, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Mozilla Firefox mozilla:firefox (from the name)	115.35 builds before 115.* not affected; 140.8 builds before 140.* not affected; from 148 not affected	CNA record
Mozilla Thunderbird mozilla:thunderbird (from the name)	140.8 builds before 140.* not affected; from 148 not affected	CNA record
mozilla firefox mozilla:firefox	before 140.8.0; before 148.0	NVD
mozilla thunderbird mozilla:thunderbird	before 140.8.0; before 148.0	NVD

References

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2009552	issue-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
https://www.mozilla.org/security/advisories/mfsa2026-31/
https://lists.debian.org/debian-lts-announce/2026/03/msg00012.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.