CVE-2026-92240CWE-125

CVE-2026-92240

Critical · published September 16, 2026

CVSS v3.1
9.1
EPSS
1%
Percentile
49.5
In the wild
Unconfirmed
What it is

A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP response parser by sending an untagged '* ID' response, crashing Thunderbird. The affected parsing path is reachable before authentication. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00628 · 49.5th percentile
Weakness
CWE-125 · Out-of-bounds Read
Published
2026-09-16T00:19Z
Affected products (3)
ProductVersionsFixed in
mozilla/thunderbird< 140.16.0140.16.0
mozilla/thunderbird≥ 141.0, < 153.3.0153.3.0
mozilla/thunderbird≥ 154.0, < 156.0156.0
References (4)
https://bugzilla.mozilla.org/show_bug.cgi?id=2069113 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-94/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-95/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-96/ · [email protected]
EPSS history
Timeline
  • 17 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 15 SEP 19:42Z
    Out-of-bounds read in IMAP response parser
    cvelistv5