# CVE-2026-124946: Firefox invalid pointer in JavaScript Engine JIT component

Source: https://junglewise.ai/threats/cve-2026-124946-invalid-pointer-in-the-javascript-engine-jit-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-2026-124946 · Severity: info · Published 2026-11-10

Firefox's JavaScript engine contains an invalid pointer vulnerability in its JIT (Just-In-Time) compilation component. This could allow an attacker to crash the browser or potentially execute arbitrary code when a user visits a malicious webpage. The vulnerability is fixed in Firefox 160.

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

## Quick answers

**Is CVE-2026-124946 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-124946 being exploited in the wild.

**How severe is CVE-2026-124946?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** Mozilla Firefox.

**Is there a fix for CVE-2026-124946?** Yes: fixed in Firefox 160. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-124946 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-124946?** Check whether you run Mozilla Firefox. 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

## Technical details

An invalid pointer in the JavaScript Engine's JIT component can lead to memory corruption when the JIT compiler processes malicious JavaScript code. This is a memory safety vulnerability that requires user interaction (visiting a malicious site) over the network. Successful exploitation could result in denial of service or code execution within the browser sandbox.

## Affected products

- Mozilla Firefox

## Timeline

- 2026-11-10: disclosed

## References

- [https://bugzilla.mozilla.org/show_bug.cgi?id=2080789](https://bugzilla.mozilla.org/show_bug.cgi?id=2080789)
- [https://www.mozilla.org/security/advisories/mfsa2026-125/](https://www.mozilla.org/security/advisories/mfsa2026-125/)

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