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TI-2020-09929 Aliases CVE-2020-12411GHSA-8mhr-8p53-r587

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 reported memory safety bugs present in Firefox 76. 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 < 77.

Why it matters now

EPSS 0.01168 67th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 77

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 7777Patch availableCNA
  • Firefox VendorMozilla Affected before 77 Fixed in 77 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 77.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 77.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 77

Fixed in the same release

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

  • Release ·

    Mozilla Firefox 77

    4 records Highest priority Priority MEDIUM 2 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2020-09927 When using certain blank characters in a URL, they where incorrectly rendered as spaces…Priority MEDIUM 40
    • TI-2020-09926 When browsing a document hosted on an IP address, an attacker could insert certain…Priority LOW 31
    • TI-2020-09925 Out-of-bounds read in Mozilla FirefoxPriority LOW 31
    Show all 4 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-12411
  2. 2026-10-03 Alias added: GHSA-8mhr-8p53-r587

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