CVE-2023-6858highCWE-787

CVE-2023-6858: high-severity vulnerability in Mozilla Firefox

Published 19 Dec 2023 · Updated 07 May 2025

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.8epss 1.5%

Firefox was susceptible to a heap buffer overflow in `nsTextFragment` due to insufficient OOM handling. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.

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

Affected products

Mozilla · Firefox Mozilla · Firefox ESR Mozilla · Thunderbird

Related CVEs — Mozilla Firefox

In the same product, most dangerous first.

CVE-2016-9079HIGHCVE-2016-9079EPSS 87.4%KEV CVE-2019-11708CRITICALCVE-2019-11708EPSS 55.9%KEV CVE-2019-17026HIGHCVE-2019-17026EPSS 46.3%KEV CVE-2019-11707HIGHCVE-2019-11707EPSS 38.0%KEV CVE-2024-9680CRITICALCVE-2024-9680EPSS 23.2%KEV CVE-2022-26485HIGHCVE-2022-26485EPSS 14.3%KEV

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1826791 https://lists.debian.org/debian-lts-announce/2023/12/msg00020.html https://lists.debian.org/debian-lts-announce/2023/12/msg00021.html https://security.gentoo.org/glsa/202401-10 https://www.debian.org/security/2023/dsa-5581 https://www.debian.org/security/2023/dsa-5582 https://www.mozilla.org/security/advisories/mfsa2023-54/https://www.mozilla.org/security/advisories/mfsa2023-55/https://www.mozilla.org/security/advisories/mfsa2023-56/