CVE-2026-124919: Mozilla Firefox privilege escalation in WebRTC Networking

CVE-2026-124919 · Severity: info · Published 2026-11-10

Firefox's WebRTC networking component contains a use-after-free vulnerability that could allow an attacker to escalate privileges on a user's system. An attacker could exploit this flaw through a malicious website to gain elevated access and run arbitrary code with higher permissions than the browser normally allows.

Technologies: Mozilla Firefox, Mozilla Firefox ESR. Vendors: Mozilla.

Quick answers

Is CVE-2026-124919 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-124919 being exploited in the wild.
How severe is CVE-2026-124919?
Informational severity, published 10 November 2026.
Which products and versions are affected?
Mozilla Firefox; Mozilla Firefox ESR.
Is there a fix for CVE-2026-124919?
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-2026-124919 attacked?
It is attacked over the network.
Am I affected by CVE-2026-124919?
Check whether you run Mozilla Firefox or Mozilla Firefox ESR. 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 use-after-free vulnerability exists in Firefox's WebRTC Networking component. The flaw allows an attacker to exploit freed memory and potentially achieve privilege escalation. The vulnerability is exploitable through network interaction with a malicious webpage.

Affected products

  • Mozilla Firefox
  • Mozilla Firefox ESR

Timeline

  • 2026-11-10: advisory

References

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