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CVE-2024-11699VulnerabilityPublished Updated

CVE-2024-11699: Memory safety bugs fixed in Firefox 133, Firefox ESR 128.5, and Thunderbird 128.5

Affects Mozilla FirefoxSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High : upgrade to 133 or 128.5 soon.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 133, 128.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 26 Nov 2024

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 26 Oct 2026.

What to do

Upgrade Mozilla Firefox to 133 or 128.5.

Affected software

ProductAffectedFixed in
Mozilla FirefoxAffected
  • <133
  • <128.5
Fixed in
  • 133
  • 128.5

AI-suggested

1. Immediate upgrade to Mozilla Firefox version 133 or later, Firefox ESR 128.5 or later, and Thunderbird 128.5 or later to apply the official patches addressing CVE-2024-11699. 2. Implement network-level protections such as web filtering to block access to known malicious sites that could exploit this vulnerability. 3. Educate users about the risks of interacting with suspicious links or email attachments to reduce the likelihood of triggering the exploit. 4. Temporarily disable or restrict JavaScript execution in Firefox where feasible, as memory corruption vulnerabilities often involve script processing. 5. Employ endpoint detection and response (EDR) solutions to monitor for unusual process behavior or memory anomalies indicative of exploitation attempts. 6. Conduct regular vulnerability scanning and asset inventory to ensure no outdated versions of Firefox or Thunderbird remain in use. 7. For organizations using centralized software deployment, enforce patch management policies that mandate timely updates of Mozilla products. 8. Review and tighten email security controls to detect and quarantine phishing emails that may carry exploit payloads. 9. Maintain up-to-date backups and incident response plans to mitigate potential damage from successful exploitation.

Description

Memory safety bugs present in Firefox 132, Firefox ESR 128.4, and Thunderbird 128.4. 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 < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.

References

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