High severity7.5NVD Advisory· Published Jul 22, 2026· Updated Aug 12, 2026
CVE-2026-14899
CVE-2026-14899
Description
The code to parse MIME headers for display when forwarding a message (if the setting to view all headers was enabled) had an off-by-one error, allowing a single byte to be read from the memory after the buffer for the headers, and potentially crashing Thunderbird. This vulnerability was fixed in Thunderbird 153 and Thunderbird 140.13.
Affected products
4before 153 and before 140.13+ 1 more
- (no CPE)range: before 153 and before 140.13
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*range: <140.13.0
- osv-coords2 versions
< 140.13.0-1.1+ 1 more
- (no CPE)range: < 140.13.0-1.1
- (no CPE)range: < 140.13.0-1.el10_2.alma.1
Patches
Vulnerability mechanics
References
3- www.mozilla.org/security/advisories/mfsa2026-71/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-72/nvdVendor Advisory
- bugzilla.mozilla.org/show_bug.cginvdPermissions Required
News mentions
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