Description

Same-origin policy bypass in the Networking: DNS component. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.

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References

Other References

https://bugzilla.mozilla.org/show_bug.cgi?id=2041001 https://www.mozilla.org/security/advisories/mfsa2026-68/ https://www.mozilla.org/security/advisories/mfsa2026-70/

Frequently Asked Questions

What is CVE-2026-16381? +

Same-origin policy bypass in the Networking: DNS component. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.

How do I check if I'm vulnerable to CVE-2026-16381? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.