CVE & CISA-KEV CatalogNVD
CVE-2026-12291
HIGH8.8
CVSS v3
Description
Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
CVSS v3 Vector
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploit Intelligence
0.30%probability of exploitation in 30 days
22ndpercentile
Low risk: more likely to be exploited than 22% of all known CVEs.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2036929
- https://www.mozilla.org/security/advisories/mfsa2026-57/
- https://www.mozilla.org/security/advisories/mfsa2026-58/
- https://www.mozilla.org/security/advisories/mfsa2026-59/
- https://www.mozilla.org/security/advisories/mfsa2026-60/
- https://www.mozilla.org/security/advisories/mfsa2026-61/
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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 2026-06-18.