Read the docs
TI-2021-06297 Aliases CVE-2021-23976GHSA-q9m5-5m39-7whx

Clickjacking in Mozilla Firefox

Priority LOW 37CWE-1021Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-1021.

Summary

When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites. Note: This issue is a different issue from CVE-2020-26954 and only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 86.

Why it matters now

EPSS 0.01096 65th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 86

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 8686Patch availableCNA
  • Firefox VendorMozilla Affected before 86 Fixed in 86 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:android:*:*before 86.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:android:*:* Versions before 86.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 86

Fixed in the same release

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

  • Advisory ·

    Mozilla Firefox — GLSA-202104-10

    12 records Highest priority Priority MEDIUM 2 MEDIUM, 10 LOW

    Other records, highest priority first

    • TI-2021-06299 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
    • TI-2021-06293 One phishing tactic on the web is to provide a link with HTTP Auth.Priority MEDIUM 40
    • TI-2021-06284 Further techniques that built on the slipstream research combined with a malicious…Priority LOW 35
    Show all 12 records → Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-23976
  2. 2026-10-03 Alias added: GHSA-q9m5-5m39-7whx

References

Advisory 3

  • 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