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TI-2023-06271 Aliases CVE-2023-6866GHSA-g9fc-wq66-mpcr

Improper handling of exceptional conditions in Mozilla Firefox

Priority MEDIUM 41CWE-755Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.

Summary

TypedArrays can be fallible and lacked proper exception handling. This could lead to abuse in other APIs which expect TypedArrays to always succeed. This vulnerability affects Firefox < 121.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00681 52nd percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 121

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

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

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 121121Patch availableCNA
  • Firefox VendorMozilla Affected before 121 Fixed in 121 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 121.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 121.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 121

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Mozilla Firefox 121

    18 records Highest priority Priority MEDIUM 8 MEDIUM, 10 LOW

    Other records, highest priority first

    • TI-2023-06261 Out-of-bounds write in Mozilla Firefox ESRPriority MEDIUM 57
    • TI-2023-06263 Out-of-bounds write in Mozilla Firefox ESRPriority MEDIUM 43
    • TI-2023-06266 Out-of-bounds write in Mozilla Firefox ESRPriority MEDIUM 41
    Show all 18 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-6866
  2. 2026-10-03 Alias added: GHSA-g9fc-wq66-mpcr

References

Advisory 2

Other 1

  • 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 3444 →

Sources

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