CVE-2026-12300 The advisory has been revoked - it doesn't affect any version of package firefox-esr (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-CHAINGUARDLATEST-FIREFOXESR-17765355
- published1 Jul 2026
- disclosed16 Jun 2026
Introduced: 16 Jun 2026
CVE-2026-12300 (opens in a new tab)Amendment
The Chainguard security team deemed this advisory irrelevant for Chainguard:latest.
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.
Memory safety bug fixed in Thunderbird 152. This vulnerability was fixed in Firefox 152 and Thunderbird 152.