# CVE-2026-124952: Firefox ESR use-after-free in Audio/Video component

Source: https://junglewise.ai/threats/cve-2026-124952-use-after-free-in-the-audio-video-component-this-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-124952 · Severity: info · Published 2026-11-10

Firefox ESR is a web browser used by organizations requiring extended support. A use-after-free vulnerability in its audio and video playback component could allow an attacker to crash the browser or execute arbitrary code if a user visits a malicious webpage or plays a crafted media file.

Technologies: [Mozilla Firefox ESR](https://junglewise.ai/threats/technologies/firefox-esr). Vendors: [Mozilla](https://junglewise.ai/threats/vendors/mozilla).

## Quick answers

**Is CVE-2026-124952 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-124952 being exploited in the wild.

**How severe is CVE-2026-124952?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** Mozilla Firefox ESR before 115.45.

**Is there a fix for CVE-2026-124952?** Yes: fixed in Firefox ESR 115.45. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-124952 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-124952?** Check whether you run Mozilla Firefox ESR at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Firefox ESR 115.45

## Technical details

A use-after-free flaw exists in Firefox ESR's Audio/Video component (CVE-2026-124952), allowing memory corruption when freed memory is accessed. The vulnerability requires user interaction (viewing a malicious website or playing crafted media) and can lead to information disclosure or code execution depending on exploit complexity.

## Affected products

- Mozilla Firefox ESR before 115.45

## Timeline

- 2026-11-10: disclosed
- 2026-11-10: patched: Fixed in Firefox ESR 115.45

## References

- [https://bugzilla.mozilla.org/show_bug.cgi?id=2071647](https://bugzilla.mozilla.org/show_bug.cgi?id=2071647)
- [https://www.mozilla.org/security/advisories/mfsa2026-126/](https://www.mozilla.org/security/advisories/mfsa2026-126/)

## Related threats

- [Firefox privilege escalation in Nimbus Desktop Client](https://junglewise.ai/threats/cve-2026-124951-privilege-escalation-in-the-nimbus-desktop-client-component-this)
- [Mozilla Firefox use-after-free in Graphics component](https://junglewise.ai/threats/cve-2026-124948-incorrect-boundary-conditions-use-after-free-in-the-graphics)
- [Firefox invalid pointer in DOM: Streams component](https://junglewise.ai/threats/cve-2026-124942-invalid-pointer-in-the-dom-streams-component-this-vulnerability)
- [Mozilla Firefox information disclosure in Security: RLBox](https://junglewise.ai/threats/cve-2026-124941-information-disclosure-in-the-security-rlbox-component-this)
- [Mozilla Firefox mitigation bypass in File Handling](https://junglewise.ai/threats/cve-2026-124940-mitigation-bypass-in-the-file-handling-component-this)