Expired Pointer Dereference The advisory has been revoked - it doesn't affect any version of package firefox (opens in a new tab)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-RHEL10-FIREFOX-19671456
- published11 Sept 2026
- disclosed1 Sept 2026
Introduced: 1 Sep 2026
CVE-2026-84121 (opens in a new tab)Amendment
The Red Hat security team deemed this advisory irrelevant for RHEL:10.
NVD Description
Note: Versions mentioned in the description apply only to the upstream firefox package and not the firefox package as distributed by RHEL.
Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2526753
- https://access.redhat.com/security/cve/CVE-2026-84121
- https://access.redhat.com/errata/RHSA-2026:67129
- https://access.redhat.com/errata/RHSA-2026:73130
- https://access.redhat.com/errata/RHSA-2026:77610
- https://access.redhat.com/errata/RHSA-2026:77631
- https://bugzilla.mozilla.org/show_bug.cgi?id=2059018
- https://www.mozilla.org/security/advisories/mfsa2026-82/
- https://www.mozilla.org/security/advisories/mfsa2026-83/
- https://www.mozilla.org/security/advisories/mfsa2026-84/
- https://www.mozilla.org/security/advisories/mfsa2026-85/
- https://www.mozilla.org/security/advisories/mfsa2026-86/
- https://www.mozilla.org/security/advisories/mfsa2026-87/
- https://www.mozilla.org/security/advisories/mfsa2026-88/