Race Condition Affecting firefox-esr package, versions <121.0-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.67% (47th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-FIREFOXESR-17764964
  • published1 Jul 2026
  • disclosed19 Dec 2023

Introduced: 19 Dec 2023

CVE-2023-6857  (opens in a new tab)
CWE-362  (opens in a new tab)

How to fix?

Upgrade Chainguard firefox-esr to version 121.0-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream firefox-esr package and not the firefox-esr package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

When resolving a symlink, a race may occur where the buffer passed to readlink may actually be smaller than necessary. This bug only affects Firefox on Unix-based operating systems (Android, Linux, MacOS). Windows is unaffected. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.

CVSS Base Scores

version 3.1