Quick answers
- Is CVE-2026-124942 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-124942 being exploited in the wild.
- How severe is CVE-2026-124942?
- Informational severity, published 10 November 2026.
- Which products and versions are affected?
- Mozilla Firefox; Mozilla Firefox ESR.
- Is there a fix for CVE-2026-124942?
- 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-2026-124942 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-124942?
- 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
An invalid pointer vulnerability exists in Firefox's DOM Streams component, allowing memory corruption when processing malformed DOM operations. The flaw requires user interaction (visiting a malicious webpage) and affects the DOM layer's stream handling. A fix is available in Firefox 160 and Firefox ESR 153.7.
Affected products
- Mozilla Firefox
- Mozilla Firefox ESR