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TI-2026-81318 Aliases CVE-2026-117992GHSA-5x3w-x79c-xmm9

Information disclosure in Mozilla Firefox and Thunderbird CSS parsing

Priority LOW 29CWE-200Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-200.

Summary

Mozilla Firefox and Thunderbird contain an information disclosure flaw in the CSS Parsing and Computation component. The flaw exposes sensitive information to an unauthorized actor (CWE-200). A remote attacker can read sensitive data when the user interacts with attacker-controlled content.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Description from the CNA

Information disclosure in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0039 33rd percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 115.44, 153.6, 159Thunderbird (Mozilla): 153.6, 159

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
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
MozillaFirefox—115.44, 153.6, 159Patch availableCNA
MozillaThunderbird—153.6, 159Patch availableCNA
  • Firefox VendorMozilla Affected — Fixed in 115.44, 153.6, 159 Patch available CNA
  • Thunderbird VendorMozilla Affected — Fixed in 153.6, 159 Patch available CNA

CPE names Threatist (inferred) · 2

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

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

Remediation

Update Firefox to 159, Firefox ESR 115.44, or Firefox ESR 153.6, and update Thunderbird to 159 or 153.6.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

  • Fix · CNA Firefox (Mozilla) Fixed in 115.44, 153.6, 159
  • Fix · CNA Thunderbird (Mozilla) Fixed in 153.6, 159

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-117992
  2. 2026-10-27 Fix available: Mozilla/Thunderbird@159 · CNA
  3. 2026-10-27 1 new reference · CNA
  4. 2026-10-27 Fix available: Mozilla/[email protected] · CNA
  5. 2026-10-27 1 new reference · CNA
  6. 2026-10-27 Alias added: GHSA-5x3w-x79c-xmm9
  7. 2026-11-05 CVSS score added · CISA ADP
  8. 2026-11-05 Weakness changed · CISA ADP
  9. 2026-11-05 CISA SSVC decision points changed

References

Other 6

  • 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