CVE-2026-14899 Affecting MozillaThunderbird package, versions <140.13.0-150200.8.280.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.47% (41st percentile)

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  • Snyk IDSNYK-SLES157-MOZILLATHUNDERBIRD-18610286
  • published11 Aug 2026
  • disclosed10 Aug 2026

Introduced: 10 Aug 2026

CVE-2026-14899  (opens in a new tab)

How to fix?

Upgrade SLES:15.7 MozillaThunderbird to version 140.13.0-150200.8.280.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream MozillaThunderbird package and not the MozillaThunderbird package as distributed by SLES. See How to fix? for SLES:15.7 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1