# CVE-2026-124938: Firefox mitigation bypass in Add-ons Manager

Source: https://junglewise.ai/threats/cve-2026-124938-mitigation-bypass-in-the-add-ons-manager-component-this  
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-2026-124938 · Severity: info · Published 2026-11-10

Mozilla Firefox, a widely used web browser, contains a vulnerability in its Add-ons Manager component that allows an attacker to bypass existing security mitigations. While the severity is reported as informational, this could potentially allow unauthorized modifications to browser extensions or addons. The vulnerability has been patched in Firefox 160 and Firefox ESR 153.7.

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

## Quick answers

**Is CVE-2026-124938 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-124938 being exploited in the wild.

**How severe is CVE-2026-124938?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** Mozilla Firefox before 160; Mozilla Firefox ESR before 153.7.

**Is there a fix for CVE-2026-124938?** Yes: fixed in Firefox 160, Firefox ESR 153.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-124938 attacked?** It is in a web application.

**Am I affected by CVE-2026-124938?** Check whether you run Mozilla Firefox or 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 160, Firefox ESR 153.7

## Technical details

A mitigation bypass exists in Firefox's Add-ons Manager component, allowing an attacker to circumvent existing security controls. The exact attack mechanism is not disclosed, but the vulnerability has been addressed with the release of Firefox 160 and Firefox ESR 153.7. Network or local access with user interaction may be required depending on the specific bypass mechanism.

## Affected products

- Mozilla Firefox before 160
- Mozilla Firefox ESR before 153.7

## Timeline

- 2026-11-10: disclosed
- 2026-11-10: patched

## References

- [https://bugzilla.mozilla.org/show_bug.cgi?id=2075948](https://bugzilla.mozilla.org/show_bug.cgi?id=2075948)
- [https://www.mozilla.org/security/advisories/mfsa2026-125/](https://www.mozilla.org/security/advisories/mfsa2026-125/)

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