CVE & CISA-KEV CatalogNVD
CVE-2026-0877
HIGH8.1
CVSS v3
Description
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
CVSS v3 Vector
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Exploit Intelligence
0.31%probability of exploitation in 30 days
23rdpercentile
Low risk: more likely to be exploited than 23% of all known CVEs.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1999257
- https://www.mozilla.org/security/advisories/mfsa2026-01/
- https://www.mozilla.org/security/advisories/mfsa2026-02/
- https://www.mozilla.org/security/advisories/mfsa2026-03/
- https://www.mozilla.org/security/advisories/mfsa2026-04/
- https://www.mozilla.org/security/advisories/mfsa2026-05/
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-13.