CVE-2024-11694: Mozilla Firefox · CSP Bypass and XSS Exposure via Web Compatibility Shims
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 6.1 Medium · fixed in 133 : update Mozilla Firefox when convenient.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 133, 128.5, 115.18
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 26 Nov 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Upgrade Mozilla Firefox to 133, 128.5 or 115.18.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in
|
AI-suggested
1. 2. If you cannot patch yet, consider temporarily disabling the Web Compatibility extension or the Google SafeFrame shim if feasible, understanding this may impact web compatibility. 3. Review and strengthen CSP policies, avoiding over-reliance on compatibility shims and ensuring frame-src directives are as restrictive as possible. 4. Implement user awareness training to reduce the risk of social engineering attacks that require user interaction. 5. Employ network-level protections such as web filtering and intrusion detection systems to block access to known malicious URLs. 6. Monitor browser telemetry and logs for unusual frame loading or script execution patterns indicative of exploitation attempts. 7. Coordinate with IT and security teams to prioritize patch management for browsers and email clients, especially in high-risk departments. 8. Consider deploying endpoint detection and response (EDR) solutions capable of detecting anomalous browser behaviors related to XSS or CSP bypass attempts.
Description
Enhanced Tracking Protection's Strict mode may have inadvertently allowed a CSP `frame-src` bypass and DOM-based XSS through the Google SafeFrame shim in the Web Compatibility extension. This issue could have exposed users to malicious frames masquerading as legitimate content. This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Firefox ESR < 115.18, Thunderbird < 133, Thunderbird < 128.5, and Thunderbird < 115.18.
References
- bugzilla.mozilla.org/show_bug.cgi?id=1924167 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2024-63/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2024-64/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2024-65/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2024-67/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2024-68/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2024-70/ (opens in a new tab)
- lists.debian.org/debian-lts-announce/2024/11/msg00029.html (opens in a new tab)