+44 1865 950 828 Secure Your Business
Actively exploitedKnown ransomware use

CVE-2024-9680 Mozilla Firefox Use-After-Free Vulnerability

Mozilla Firefox and Firefox ESR contain a use-after-free vulnerability in Animation timelines that allows for code execution in the content process.

From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.

Our Assessment

Should You Worry?

Patch nowCybergen assessment
  • CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 15 Oct 2024.
  • CISA lists it as known to be used in ransomware campaigns.
  • Rated Critical severity (CVSS 9.8, scored by CISA).
  • It has been in the catalogue for 752 days. Systems still unpatched now have almost certainly been scanned for it.
The Vulnerability

What It Is

An attacker was able to achieve code execution in the content process by exploiting a use-after-free in Animation timelines. We have had reports of this vulnerability being exploited in the wild. This vulnerability affects Firefox < 131.0.2, Firefox ESR < 128.3.1, Firefox ESR < 115.16.1, Thunderbird < 131.0.1, Thunderbird < 128.3.1, and Thunderbird < 115.16.0.

Affected Versions

ProductVersions
Mozilla Firefoxunspecified to before 131.0.2
Mozilla Firefox ESRunspecified to before 128.3.1
Mozilla Firefox ESRunspecified to before 115.16.1
Mozilla Thunderbirdunspecified to before 131.0.1
Mozilla Thunderbirdunspecified to before 128.3.1
Mozilla Thunderbirdunspecified to before 115.16.0

From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.

From Watch to Action

What To Do Now

  1. 1

    Find it

    Search your asset inventory and external attack surface for Mozilla Firefox. Include cloud images, appliances and anything a supplier runs for you.

    Attack Surface Management
  2. 2

    Fix it

    Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

    Vulnerability Management
  3. 3

    Hunt for compromise

    If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.

    Incident Response
  4. 4

    Prove it is fixed

    Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.

    Penetration Testing

Vendor Advisories

Regulation

The Compliance Clock

Cyber EssentialsRated critical, so if it affects devices in your Cyber Essentials scope, the update must be installed within 14 days of the vendor releasing it.NIS2If exploitation causes a significant incident, essential and important entities owe their CSIRT an early warning within 24 hours and a notification within 72 hours.DORAFinancial entities must classify ICT incidents and send an initial notification for a major incident within strict deadlines, with exploited flaws a common cause.US federal (BOD 22-01)Federal civilian agencies had until 5 Nov 2024 to remediate. A sensible benchmark for everyone else.

General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.

Stay Ahead

More Exploited Mozilla Flaws

Get alerts for MozillaWe email you when a new Mozilla vulnerability is confirmed as exploited. Add more vendors on Threat Watch.

By signing up you agree to receive Threat Watch alerts. Unsubscribe at any time. See our Privacy Policy.

CVE-2010-3765Mozilla Multiple Products Remote Code Execution VulnerabilityAdded 6 Oct 2025CVE-2016-9079Mozilla Firefox, Firefox ESR, and Thunderbird Use-After-Free VulnerabilityAdded 22 Jun 2023CVE-2015-4495Mozilla Firefox Security Feature Bypass VulnerabilityAdded 25 May 2022CVE-2019-11707Mozilla Firefox and Thunderbird Type Confusion VulnerabilityAdded 23 May 2022CVE-2019-11708Mozilla Firefox and Thunderbird Sandbox Escape VulnerabilityAdded 23 May 2022CVE-2013-1690Mozilla Firefox and Thunderbird Denial-of-Service VulnerabilityAdded 28 Mar 2022

All 13 exploited Mozilla vulnerabilities

Not Sure If You Are Exposed?

Our attack surface and vulnerability teams can check your internet-facing estate for CVE-2024-9680 and every other exploited flaw on the list.

Check My Exposure
Evidence

Sources

  1. CISA Known Exploited Vulnerabilities catalogue
  2. NVD: CVE-2024-9680
  3. CVE record: CVE-2024-9680
  4. FIRST EPSS
  5. mozilla.org/en-US/security/advisories/mfsa2024-51/
  6. bugzilla.mozilla.org/show_bug.cgi?id=1923344
  7. msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2024-49039
  8. mozilla.org/security/advisories/mfsa2024-51/
  9. mozilla.org/security/advisories/mfsa2024-52/