Sandbox escape due to use-after-free in the XPCOM component
CVE-2026-118021

Currently unrated

Key Information:

Vendor: Mozilla
Status: Firefox
Vendor: CVE Published:; 27 October 2026

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What is CVE-2026-118021?

Sandbox escape due to use-after-free in the XPCOM component. This vulnerability was fixed in Firefox 159.

Affected Version(s)

Firefox 159

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2076695

https://www.mozilla.org/security/advisories/mfsa2026-118/

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Timeline

Vulnerability published
Oct 27, 2026
Vulnerability Reserved
Oct 27, 2026

Credit

Mozilla

CVE-2026-118021 Data

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