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TI-2026-81512 Aliases CVE-2026-118180GHSA-x88m-7whj-m9mh

Matrix homeserver can redirect Thunderbird session to local files

Priority LOW 39CWE-601Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-601.

Summary

Mozilla Thunderbird does not validate the homeserver address that a Matrix login response provides. A malicious or compromised homeserver can supply a file: URL, so Thunderbird sends all further Matrix requests of that session to local files or, on Windows, to an attacker-controlled network share (CWE-601). On Windows this can leak the user's NTLM credentials. The flaw is reachable over the network and needs no privileges or user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

When logging in to a Matrix account, Thunderbird used the homeserver address provided in the server's login response without validating it. A malicious or compromised homeserver could provide a file: URL, causing Thunderbird to send all further Matrix requests of that session to local files or, on Windows, to an attacker-controlled network share, which could leak the user's NTLM credentials. The NTLM credential leak only affects Thunderbird on Windows. Other operating systems are unaffected. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00324 25th percentileScored 2026-11-07
Fix Partial Thunderbird (Mozilla): 153.6, 159Red Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaThunderbird—153.6, 159Patch availableCNA
  • Thunderbird VendorMozilla Affected — Fixed in 153.6, 159 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*——Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions — — ·Mozilla

Remediation

Update Thunderbird to version 153.6 or 159, which fix this flaw. Red Hat rates it Moderate. The sources list no fixed version for Red Hat Enterprise Linux 8, 9 and 10, and no fix planned for Red Hat Enterprise Linux 6 and 7.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA Thunderbird (Mozilla) Fixed in 153.6, 159

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-118180
  2. 2026-10-27 Fix available: Mozilla/[email protected] · CNA
  3. 2026-10-27 1 new reference · CNA
  4. 2026-10-27 Alias added: GHSA-x88m-7whj-m9mh
  5. 2026-10-29 Affected versions changed · Red Hat
  6. 2026-10-29 CVSS score added · Red Hat
  7. 2026-10-30 Affected versions changed · Red Hat
  8. 2026-10-30 CVSS score changed · Red Hat
  9. 2026-11-02 Affected versions changed · Red Hat
  10. 2026-11-04 CVSS score added · CISA ADP
  11. 2026-11-04 Weakness changed · CISA ADP
  12. 2026-11-04 CISA SSVC decision points changed
  13. 2026-11-06 Affected versions changed · Red Hat

References

Other 3

  • 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
See all 4204 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences