CVE-2026-100780
highUse-after-free in the DOM: Core & HTML component.
Vendor / product: Mozilla — firefox
Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
CVSS
8.8
8.8 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Severity source: NVD CVSS v3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
Timeline (UTC)
Published: 2026-09-29 13:17
Modified: 2026-10-05 15:12
NVD status: Analyzed
Last synced 2 days ago
Verified against the source API 2026-10-27 06:56 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
mozilla / firefox <157.0.0, ≥115.1.0 <115.42.0, ≥140.0 <140.17.0, ≥153.0 <153.4.0
mozilla / thunderbird <157.0, ≥140.0 <140.17.0, ≥153.0 <153.4.0
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2026-100/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2026-101/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2026-102/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2026-103/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2026-97/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2026-98/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2026-99/
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2068422 security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-100/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-101/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-102/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-103/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-97/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-98/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-99/ security@mozilla.org
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 06:56 UTC · record ↗