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TI-2021-10564 Aliases CVE-2021-29947GHSA-m9m4-w6qg-qgcp

Out-of-bounds write in Mozilla Firefox

Priority MEDIUM 40CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · 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

Mozilla developers and community members reported memory safety bugs present in Firefox 87. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 88.

Why it matters now

EPSS 0.00867 58th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 88

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 8888Patch availableCNA
  • Firefox VendorMozilla Affected before 88 Fixed in 88 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 88.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 88.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 88

Fixed in the same release

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

  • Release ·

    Mozilla Firefox 88

    13 records Highest priority Priority MEDIUM 7 MEDIUM, 6 LOW

    Other records, highest priority first

    • TI-2021-06313 Missing initialization of resource in Mozilla Firefox ESRPriority MEDIUM 42
    • TI-2021-10563 Integer overflow in Mozilla Firefox ESRPriority MEDIUM 41
    • TI-2021-06318 Improper privilege management in Mozilla Firefox ESRPriority MEDIUM 41
    Show all 13 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-29947
  2. 2026-10-03 Alias added: GHSA-m9m4-w6qg-qgcp

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