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TI-2021-06304 Aliases CVE-2021-23983GHSA-cx32-x9h5-xm6c

Out-of-bounds write in Mozilla Firefox

Priority LOW 30CWE-787Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.

Summary

By causing a transition on a parent node by removing a CSS rule, an invalid property for a marker could have been applied, resulting in memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 87.

Why it matters now

EPSS 0.00736 54th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 87

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 8787Patch availableCNA
  • Firefox VendorMozilla Affected before 87 Fixed in 87 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 87.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 87.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 87

Fixed in the same release

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

  • Release ·

    Mozilla Firefox 87

    8 records Highest priority Priority MEDIUM 2 MEDIUM, 6 LOW

    Other records, highest priority first

    • TI-2021-06308 Out-of-bounds write in Mozilla Firefox ESRPriority MEDIUM 41
    • TI-2021-06309 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 40
    • TI-2021-06302 Out-of-bounds write in Mozilla Firefox ESRPriority LOW 38
    Show all 8 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-23983
  2. 2026-10-03 Alias added: GHSA-cx32-x9h5-xm6c

References

Advisory 2

  • 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