VULNERABILITY INTELLIGENCE

CVE-2026-14899

CVSS score7.5 HIGH
EPSS probability0.47%
CISA KEVNot currently listed
Published2026-07-22
Last modified2026-10-24
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

Weakness classification

  • 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-193

Primary references