Out-of-bounds Read The advisory has been revoked - it doesn't affect any version of package thunderbird (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RHEL10-THUNDERBIRD-18339527
- published28 Jul 2026
- disclosed22 Jul 2026
Introduced: 22 Jul 2026
CVE-2026-14899 (opens in a new tab)Amendment
The Red Hat security team deemed this advisory irrelevant for RHEL:10.
NVD Description
Note: Versions mentioned in the description apply only to the upstream thunderbird package and not the thunderbird package as distributed by RHEL.
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.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2506217
- https://access.redhat.com/security/cve/CVE-2026-14899
- https://access.redhat.com/errata/RHSA-2026:49621
- https://bugzilla.mozilla.org/show_bug.cgi?id=2046137
- https://www.mozilla.org/security/advisories/mfsa2026-71/
- https://www.mozilla.org/security/advisories/mfsa2026-72/