CVE-2026-4371
CVE-2026-4371 · Out of bounds read in IMAP parsing
This page contains facts from public vulnerability sources. Check the original advisory before updating.
A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.
CVSS 7.4 · High · EPSS 0.4% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
thunderbird
- Versions
- ≥ 140.9, ≤ 140.*: Not affected (rpm)
- ≥ 149: Not affected (rpm)
No fix published
thunderbird Debian:12
- Versions
- 1:102.11.0-1
- 1:102.12.0-1
- 1:102.12.0-1~deb10u1
- 1:102.12.0-1~deb11u1
- 1:102.12.0-1~deb12u1
- 1:102.13.0-1
- 1:102.13.0-1~deb10u1
- 1:102.13.0-1~deb11u1
- 1:102.13.0-1~deb12u1
- 1:102.13.1-1
- 1:102.13.1-1~deb10u1
- 1:102.13.1-1~deb11u1
- 1:102.13.1-1~deb12u1
- 1:102.14.0-1~deb10u1
- 1:102.14.0-1~deb11u1
- 1:102.14.0-1~deb12u1
- 1:102.15.0-1~deb10u1
- 1:102.15.0-1~deb11u1
- 1:102.15.0-1~deb12u1
- 1:102.15.1-1~deb10u1
- 1:102.15.1-1~deb11u1
- 1:102.15.1-1~deb12u1
- 1:103.0~b5-1
- 1:104.0~b2-1
- 1:110.0~b4-1
- 1:112.0~b1-1
- 1:113.0~b3-1
- 1:114.0~b2-1
- 1:115.0-1
- 1:115.0.1-1
- 1:115.0.1-2
- 1:115.0~b4-1
- 1:115.0~b6-1
- 1:115.1.0-1
- 1:115.1.1-1
- 1:115.10.1-1
- 1:115.10.1-1~deb10u1
- 1:115.10.1-1~deb11u1
- 1:115.10.1-1~deb12u1
- 1:115.11.0-1
- 1:115.11.0-1~deb10u1
- 1:115.11.0-1~deb11u1
- 1:115.11.0-1~deb12u1
- 1:115.12.0-1
- 1:115.12.0-1~deb10u1
- 1:115.12.0-1~deb11u1
- 1:115.12.0-1~deb12u1
- 1:115.13.0-1
- 1:115.13.0-1~deb11u1
- 1:115.13.0-1~deb12u1
- 1:115.14.0-1~deb11u1
- 1:115.14.0-1~deb12u1
- 1:115.15.0-1~deb11u1
- 1:115.15.0-1~deb12u1
- 1:115.16.0esr-1~deb11u1
- 1:115.16.0esr-1~deb12u1
- 1:115.2.0-1
- 1:115.2.2-1
- 1:115.3.0-1
- 1:115.3.0-1~deb12u1
- 1:115.3.1-1
- 1:115.3.1-1~deb10u1
- 1:115.3.1-1~deb11u1
- 1:115.3.1-1~deb12u1
- 1:115.4.1-1
- 1:115.4.1-1~deb10u1
- 1:115.4.1-1~deb11u1
- 1:115.4.1-1~deb12u1
- 1:115.5.0-1
- 1:115.5.0-1~deb10u1
- 1:115.5.0-1~deb11u1
- 1:115.5.0-1~deb12u1
- 1:115.5.1-1
- 1:115.5.2-1
- 1:115.6.0-1
- 1:115.6.0-1~deb10u1
- 1:115.6.0-1~deb11u1
- 1:115.6.0-1~deb12u1
- 1:115.7.0-1
- 1:115.7.0-1~deb10u1
- 1:115.7.0-1~deb11u1
- 1:115.7.0-1~deb12u1
- 1:115.8.0-1
- 1:115.8.0-1~deb10u1
- 1:115.8.0-1~deb11u1
- 1:115.8.0-1~deb12u1
- 1:115.8.1-1
- 1:115.9.0-1
- 1:115.9.0-1~deb10u1
- 1:115.9.0-1~deb11u1
- 1:115.9.0-1~deb12u1
- 1:116.0~b7-1
- 1:117.0~b5-1
- 1:120.0~b1-1
- 1:121.0~b3-1
- 1:122.0~b2-1
- 1:124.0~b5-1
- 1:125.0~b3-1
- 1:127.0~b5-1
- 1:128.0esr-1
- 1:128.0~b5-1
- 1:128.1.0esr-1
- 1:128.1.1esr-1
- 1:128.10.0esr-1
- 1:128.10.0esr-1~deb11u1
- 1:128.10.0esr-1~deb12u1
- 1:128.10.1esr-1
- 1:128.10.1esr-1~deb11u1
- 1:128.10.1esr-1~deb12u1
- 1:128.11.0esr-1
- 1:128.11.0esr-1~deb11u1
- 1:128.11.0esr-1~deb12u1
- 1:128.12.0esr-1
- 1:128.12.0esr-1~deb11u1
- 1:128.12.0esr-1~deb12u1
- 1:128.13.0esr-1
- 1:128.13.0esr-1~deb11u1
- 1:128.13.0esr-1~deb12u1
- 1:128.14.0esr-1
- 1:128.14.0esr-1~deb11u1
- 1:128.14.0esr-1~deb12u1
- 1:128.14.0esr-1~deb13u1
- 1:128.2.0esr-1
- 1:128.2.1esr-1
- 1:128.2.3esr-1
- 1:128.3.0esr-1
- 1:128.3.2esr-1
- 1:128.4.0esr-1
- 1:128.4.0esr-1~deb11u1
- 1:128.4.0esr-1~deb12u1
- 1:128.4.2esr-1
- 1:128.4.3esr-1
- 1:128.4.3esr-1~deb11u1
- 1:128.4.3esr-1~deb12u1
- 1:128.5.0esr-1
- 1:128.5.0esr-1~deb11u1
- 1:128.5.0esr-1~deb12u1
- 1:128.5.2esr-1
- 1:128.6.0esr-1
- 1:128.6.0esr-1~deb11u1
- 1:128.6.0esr-1~deb12u1
- 1:128.7.0esr-1
- 1:128.7.0esr-1~deb11u1
- 1:128.7.0esr-1~deb12u1
- 1:128.8.0esr-1
- 1:128.8.0esr-1~deb11u1
- 1:128.8.0esr-1~deb12u1
- 1:128.9.0esr-1
- 1:128.9.0esr-1~deb11u1
- 1:128.9.0esr-1~deb12u1
- 1:129.0~b6-1
- 1:130.0~b3-1
- 1:132.0~b6-1
- 1:135.0-1
- 1:136.0-1
- 1:137.0-1
- 1:138.0-1
- 1:140.0.1esr-1
- 1:140.1.0esr-1
- 1:140.1.1esr-1
- 1:140.2.0esr-1
- 1:140.3.0esr-1
- 1:140.3.0esr-1~deb11u1
- 1:140.3.0esr-1~deb12u1
- 1:140.3.0esr-1~deb13u1
- 1:140.3.1esr-1
- 1:140.4.0esr-1
- 1:140.4.0esr-1~deb11u1
- 1:140.4.0esr-1~deb12u1
- 1:140.4.0esr-1~deb13u1
- 1:140.5.0esr-1
- 1:140.5.0esr-1~deb11u1
- 1:140.5.0esr-1~deb12u1
- 1:140.5.0esr-1~deb13u1
- 1:140.6.0esr-1
- 1:140.6.0esr-1~deb11u1
- 1:140.6.0esr-1~deb12u1
- 1:140.6.0esr-1~deb13u1
- 1:140.7.0esr-1
- 1:140.7.0esr-1~deb11u1
- 1:140.7.0esr-1~deb12u1
- 1:140.7.0esr-1~deb13u1
- 1:140.7.1esr-1
- 1:140.7.1esr-1~deb11u1
- 1:140.7.1esr-1~deb12u1
- 1:140.7.1esr-1~deb13u1
- 1:140.8.0esr-1
- 1:140.8.0esr-1~deb11u1
- 1:140.8.0esr-1~deb12u1
- 1:140.8.0esr-1~deb13u1
- 1:140.9.0esr-1~deb11u1
- Affected ranges
- ECOSYSTEM: < 1:140.9.0esr-1~deb12u1
Update to 1:140.9.0esr-1~deb12u1
thunderbird Debian:13
- Versions
- 1:128.13.0esr-1
- 1:128.14.0esr-1
- 1:128.14.0esr-1~deb11u1
- 1:128.14.0esr-1~deb12u1
- 1:128.14.0esr-1~deb13u1
- 1:129.0~b6-1
- 1:130.0~b3-1
- 1:132.0~b6-1
- 1:135.0-1
- 1:136.0-1
- 1:137.0-1
- 1:138.0-1
- 1:140.0.1esr-1
- 1:140.1.0esr-1
- 1:140.1.1esr-1
- 1:140.2.0esr-1
- 1:140.3.0esr-1
- 1:140.3.0esr-1~deb11u1
- 1:140.3.0esr-1~deb12u1
- 1:140.3.0esr-1~deb13u1
- 1:140.3.1esr-1
- 1:140.4.0esr-1
- 1:140.4.0esr-1~deb11u1
- 1:140.4.0esr-1~deb12u1
- 1:140.4.0esr-1~deb13u1
- 1:140.5.0esr-1
- 1:140.5.0esr-1~deb11u1
- 1:140.5.0esr-1~deb12u1
- 1:140.5.0esr-1~deb13u1
- 1:140.6.0esr-1
- 1:140.6.0esr-1~deb11u1
- 1:140.6.0esr-1~deb12u1
- 1:140.6.0esr-1~deb13u1
- 1:140.7.0esr-1
- 1:140.7.0esr-1~deb11u1
- 1:140.7.0esr-1~deb12u1
- 1:140.7.0esr-1~deb13u1
- 1:140.7.1esr-1
- 1:140.7.1esr-1~deb11u1
- 1:140.7.1esr-1~deb12u1
- 1:140.7.1esr-1~deb13u1
- 1:140.8.0esr-1
- 1:140.8.0esr-1~deb11u1
- 1:140.8.0esr-1~deb12u1
- 1:140.8.0esr-1~deb13u1
- 1:140.9.0esr-1~deb11u1
- 1:140.9.0esr-1~deb12u1
- Affected ranges
- ECOSYSTEM: < 1:140.9.0esr-1~deb13u1
Update to 1:140.9.0esr-1~deb13u1
thunderbird Debian:14
- Versions
- 1:128.13.0esr-1
- 1:128.14.0esr-1
- 1:128.14.0esr-1~deb11u1
- 1:128.14.0esr-1~deb12u1
- 1:128.14.0esr-1~deb13u1
- 1:129.0~b6-1
- 1:130.0~b3-1
- 1:132.0~b6-1
- 1:135.0-1
- 1:136.0-1
- 1:137.0-1
- 1:138.0-1
- 1:140.0.1esr-1
- 1:140.1.0esr-1
- 1:140.1.1esr-1
- 1:140.2.0esr-1
- 1:140.3.0esr-1
- 1:140.3.0esr-1~deb11u1
- 1:140.3.0esr-1~deb12u1
- 1:140.3.0esr-1~deb13u1
- 1:140.3.1esr-1
- 1:140.4.0esr-1
- 1:140.4.0esr-1~deb11u1
- 1:140.4.0esr-1~deb12u1
- 1:140.4.0esr-1~deb13u1
- 1:140.5.0esr-1
- 1:140.5.0esr-1~deb11u1
- 1:140.5.0esr-1~deb12u1
- 1:140.5.0esr-1~deb13u1
- 1:140.6.0esr-1
- 1:140.6.0esr-1~deb11u1
- 1:140.6.0esr-1~deb12u1
- 1:140.6.0esr-1~deb13u1
- 1:140.7.0esr-1
- 1:140.7.0esr-1~deb11u1
- 1:140.7.0esr-1~deb12u1
- 1:140.7.0esr-1~deb13u1
- 1:140.7.1esr-1
- 1:140.7.1esr-1~deb11u1
- 1:140.7.1esr-1~deb12u1
- 1:140.7.1esr-1~deb13u1
- 1:140.8.0esr-1
- 1:140.8.0esr-1~deb11u1
- 1:140.8.0esr-1~deb12u1
- 1:140.8.0esr-1~deb13u1
- 1:140.9.0esr-1~deb11u1
- 1:140.9.0esr-1~deb12u1
- 1:140.9.0esr-1~deb13u1
- Affected ranges
- ECOSYSTEM: < 1:140.9.0esr-1
Update to 1:140.9.0esr-1
mozjs52 Ubuntu:18.04:LTS
- Versions
- 52.3.1-0ubuntu3
- 52.3.1-7fakesync1
- 52.8.1-0ubuntu0.18.04.1
- 52.9.1-0ubuntu0.18.04.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
mozjs38 Ubuntu:18.04:LTS
- Versions
- 38.8.0~repack1-0ubuntu1
- 38.8.0~repack1-0ubuntu3
- 38.8.0~repack1-0ubuntu4
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
mozjs68 Ubuntu:20.04:LTS
- Versions
- 68.5.0-1~fakesync
- 68.5.0-2~fakesync
- 68.6.0-1
- 68.6.0-1ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
mozjs52 Ubuntu:20.04:LTS
- Versions
- 52.9.1-1build1
- 52.9.1-1ubuntu3
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
mozjs102 Ubuntu:22.04:LTS
- Versions
- 102.11.0-0ubuntu0.22.04.1
- 102.12.0-0ubuntu0.22.04.1
- 102.13.0-0ubuntu0.22.04.1
- 102.15.1-0ubuntu0.22.04.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
mozjs78 Ubuntu:22.04:LTS
- Versions
- 78.13.0-1
- 78.15.0-2
- 78.15.0-4ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
mozjs91 Ubuntu:22.04:LTS
- Versions
- 91.5.1-0ubuntu1
- 91.6.0-1
- 91.6.0-2
- 91.7.0-2
- 91.10.0-0ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
thunderbird Ubuntu:22.04:LTS
- Versions
- 1:91.1.2+build1-0ubuntu1
- 1:91.3.0+build2-0ubuntu1
- 1:91.3.1+build1-0ubuntu1
- 1:91.3.2+build1-0ubuntu1
- 1:91.4.0+build1.1-0ubuntu1
- 1:91.4.0+build2-0ubuntu1
- 1:91.5.0+build1-0ubuntu1
- 1:91.5.1+build1-0ubuntu1
- 1:91.6.1+build1-0ubuntu1
- 1:91.7.0+build1-0ubuntu1
- 1:91.7.0+build2-0ubuntu1
- 1:91.8.0+build2-0ubuntu1
- 1:91.9.1+build1-0ubuntu0.22.04.1
- 1:91.11.0+build2-0ubuntu0.22.04.1
- 1:102.2.2+build1-0ubuntu0.22.04.1
- 1:102.4.2+build2-0ubuntu0.22.04.1
- 1:102.7.1+build2-0ubuntu0.22.04.1
- 1:102.8.0+build2-0ubuntu0.22.04.1
- 1:102.9.0+build1-0ubuntu0.22.04.1
- 1:102.10.0+build2-0ubuntu0.22.04.1
- 1:102.11.0+build1-0ubuntu0.22.04.1
- 1:102.13.0+build1-0ubuntu0.22.04.1
- 1:102.15.0+build1-0ubuntu0.22.04.1
- 1:102.15.1+build1-0ubuntu0.22.04.1
- 1:115.3.1+build1-0ubuntu0.22.04.2
- 1:115.4.1+build1-0ubuntu0.22.04.1
- 1:115.5.0+build1-0ubuntu0.22.04.1
- 1:115.6.0+build2-0ubuntu0.22.04.1
- 1:115.8.1+build1-0ubuntu0.22.04.1
- 1:115.9.0+build1-0ubuntu0.22.04.1
- 1:115.10.1+build1-0ubuntu0.22.04.1
- 1:115.11.0+build2-0ubuntu0.22.04.1
- 1:115.12.0+build3-0ubuntu0.22.04.1
- 1:115.13.0+build5-0ubuntu0.22.04.1
- 1:115.15.0+build1-0ubuntu0.22.04.1
- 1:115.16.0+build2-0ubuntu0.22.04.1
- 1:115.18.0+build1-0ubuntu0.22.04.1
- 1:128.12.0+build1-0ubuntu0.22.04.1
- 1:140.7.1+build1-0ubuntu0.22.04.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
mozjs102 Ubuntu:24.04:LTS
- Versions
- 102.15.1-1
- 102.15.1-3ubuntu2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
mozjs115 Ubuntu:24.04:LTS
- Versions
- 115.3.0-0ubuntu1
- 115.4.0-2
- 115.5.0-1
- 115.6.0-1
- 115.7.0-4
- 115.8.0-1
- 115.9.0-1
- 115.9.0-1build1
- 115.10.0-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
Original sources
- https://bugzilla.mozilla.org/show_bug.cgi?id=2023493
- https://www.mozilla.org/security/advisories/mfsa2026-23/
- https://www.mozilla.org/security/advisories/mfsa2026-24/
- https://access.redhat.com/security/cve/CVE-2026-4371
- https://bugzilla.redhat.com/show_bug.cgi?id=2451001
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4371.json
- https://access.redhat.com/errata/RHSA-2026:8315
- https://access.redhat.com/errata/RHSA-2026:6342
- https://access.redhat.com/errata/RHSA-2026:6917
- https://access.redhat.com/errata/RHSA-2026:8285
- https://access.redhat.com/errata/RHSA-2026:8850
- https://access.redhat.com/errata/RHSA-2026:8289
- https://access.redhat.com/errata/RHSA-2026:8288
- https://access.redhat.com/errata/RHSA-2026:8286
- https://access.redhat.com/errata/RHSA-2026:8287
- https://access.redhat.com/errata/RHSA-2026:8290
- https://access.redhat.com/errata/RHSA-2026:8284
- https://access.redhat.com/errata/RHSA-2026:6188
- https://nvd.nist.gov/vuln/detail/CVE-2026-4371