CVE-2026-109733

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

CVSS 3.1

8.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

EPSS

0.5% chance of exploitation in the next 30 days; higher than 39% of CVEs (scores of 2026-10-25)

CWE

CWE-843

Published

2026-10-13

Modified

2026-10-15

Record from

the NVD, synced 2026-10-19

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2076269
• https://www.mozilla.org/security/advisories/mfsa2026-106/
• https://www.mozilla.org/security/advisories/mfsa2026-107/
• https://www.mozilla.org/security/advisories/mfsa2026-108/
• https://www.mozilla.org/security/advisories/mfsa2026-109/

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