CVE-2023-5172: Mozilla Firefox

Critical severity, CVSS 9.8. EPSS: 1% chance of exploitation in the next 30 days.

A hashtable in the Ion Engine could have been mutated while there was a live interior reference, leading to a potential use-after-free and exploitable crash. This vulnerability affects Firefox < 118.

Affected products

• Mozilla Firefox: before 118 (fixed in 118)

Published 2023-09-27. Last modified 2026-06-17.