{"cve":"CVE-2023-5171","nvd":{"published":"2023-09-27T15:19:42.227","modified":"2026-06-17T06:47:42.753","status":"Modified","description":"During Ion compilation, a Garbage Collection could have resulted in a use-after-free condition, allowing an attacker to write two NUL bytes, and cause a potentially exploitable crash. This vulnerability affects Firefox < 118, Firefox ESR < 115.3, and Thunderbird < 115.3.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-416"],"references":["https://bugzilla.mozilla.org/show_bug.cgi?id=1851599","https://lists.debian.org/debian-lts-announce/2023/09/msg00034.html","https://lists.debian.org/debian-lts-announce/2023/10/msg00015.html","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/AY642Z6JZODQJE7Z62CFREVUHEGCXGPD/","https://www.debian.org/security/2023/dsa-5506"],"products":["debian:debian_linux","fedoraproject:fedora","mozilla:firefox","mozilla:firefox_esr","mozilla:thunderbird"],"source":"nvd","synced_at":"2026-10-19T21:39:34.467980132+00:00"},"epss":{"cve":"CVE-2023-5171","score":0.01116,"percentile":0.66083,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}