Ambiguous parsing of mail headers
Priority MEDIUM 50CWE-444Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 13 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00539 45th percentileScored 2026-11-07
Fix Partial Thunderbird (Mozilla): 140.16, 153.3, 156Red Hat: 10 advisoriesRed Hat: 13 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Thunderbird | — | 140.16, 153.3, 156 | Patch available | CNA |
- Thunderbird VendorMozilla Affected — Fixed in 140.16, 153.3, 156 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 140.16.0; 141.0 to before 153.3.0; 154.0 to before 156.0 | Vulnerable | Mozilla |
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 140.16.0; 141.0 to before 153.3.0; 154.0 to before 156.0 Vulnerable ·Mozilla
Remediation
- Fix · CNA Thunderbird (Mozilla) Fixed in 140.16, 153.3, 156
Red Hat 10 advisories
- RHSA-2026:82122 Released 2026-10-13 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-140.16.0-1.el8_4
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) thunderbird-140.16.0-1.el8_4
- RHSA-2026:81912 Released 2026-10-13 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) thunderbird-140.16.0-1.el8_8
- Red Hat Enterprise Linux AppStream TUS (v.8.8) thunderbird-140.16.0-1.el8_8
- RHSA-2026:81884 Released 2026-10-13 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-140.16.0-1.el9_6
Show 7 more Red Hat advisories
- RHSA-2026:81913 Released 2026-10-13 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird-140.16.0-1.el8_6
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) thunderbird-140.16.0-1.el8_6
- RHSA-2026:81393 Released 2026-10-12 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) thunderbird-140.16.0-1.el9_4
- RHSA-2026:81392 Released 2026-10-12 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) thunderbird-140.16.0-1.el10_0
- RHSA-2026:81394 Released 2026-10-12 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) thunderbird-140.16.0-1.el9_2
- RHSA-2026:73971 Released 2026-09-30 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-140.16.0-1.el8_10
- RHSA-2026:73130 Released 2026-09-29 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 10) thunderbird-140.16.0-1.el10_2
- RHSA-2026:70642 Released 2026-09-24 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.16.0-1.el9_8
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:73130 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:73971 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:70642 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2026:82122 |
| Red Hat Enterprise Linux AppStream AUS (v.8.6) | Fixed | RHSA-2026:81913 |
| Red Hat Enterprise Linux AppStream E4S (v.8.8) | Fixed | RHSA-2026:81912 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:81394 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:81393 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:81392 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:81884 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) | Fixed | RHSA-2026:82122 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) | Fixed | RHSA-2026:81913 |
| Red Hat Enterprise Linux AppStream TUS (v.8.8) | Fixed | RHSA-2026:81912 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-92238
- 2026-10-03 Alias added: GHSA-w2rw-r9p8-wp72
- 2026-10-12 Fix available: RHSA-2026:81392 · Red Hat
- 2026-10-12 Fix available: RHSA-2026:81394 · Red Hat
- 2026-10-13 Fix available: RHSA-2026:81393 · Red Hat
- 2026-10-13 Fix available: RHSA-2026:81912 · Red Hat
- 2026-10-13 Fix available: RHSA-2026:81913 · Red Hat
- 2026-10-13 Fix available: RHSA-2026:81884 · Red Hat
- 2026-10-13 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream E4S (v.8.8) +7 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82122 · Red Hat
References
More Mozilla Thunderbird vulnerabilities
- TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
- TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
- TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
- TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2026-92238 · CVE Program
- CVE-2026-92238 · NVD
- FIRST EPSS
- GHSA-w2rw-r9p8-wp72 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-92238 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences