--- id: CVE-2026-74944 title: 'Use-after-free in the DOM: Core & HTML component' summary: >- Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. severity: critical cvss: 9.8 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H' cwe: - CWE-416 - CWE-416 vendor: mozilla product: firefox affected: - firefox < 140.14.0 - 'firefox >= 141.0.0, < 153.1.0' - thunderbird < 140.14.0 - 'thunderbird >= 141.0, < 153.1.0' patched: - firefox 153.1.0 - thunderbird 153.1.0 published: '2026-08-18' updated: '2026-08-21' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74944' references: - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=2057778' label: security@mozilla.org - url: 'https://www.mozilla.org/security/advisories/mfsa2026-74/' label: security@mozilla.org - url: 'https://www.mozilla.org/security/advisories/mfsa2026-76/' label: security@mozilla.org - url: 'https://www.mozilla.org/security/advisories/mfsa2026-77/' label: security@mozilla.org - url: 'https://www.mozilla.org/security/advisories/mfsa2026-78/' label: security@mozilla.org - url: 'https://www.mozilla.org/security/advisories/mfsa2026-79/' label: security@mozilla.org - url: 'https://www.mozilla.org/security/advisories/mfsa2026-80/' label: security@mozilla.org - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74944.json - url: 'https://access.redhat.com/security/cve/CVE-2026-74944' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2517868' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-74944' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74944' - url: 'https://www.mozilla.org/security/advisories/mfsa2026-76/#CVE-2026-74944' - url: 'https://www.mozilla.org/security/advisories/mfsa2026-79/#CVE-2026-74944' - url: 'https://access.redhat.com/errata/RHSA-2026:64813' - url: 'https://access.redhat.com/errata/RHSA-2026:58899' - url: 'https://access.redhat.com/errata/RHSA-2026:58898' - url: 'https://access.redhat.com/errata/RHSA-2026:65111' - url: 'https://access.redhat.com/errata/RHSA-2026:64814' - url: 'https://access.redhat.com/errata/RHSA-2026:58897' - url: 'https://access.redhat.com/errata/RHSA-2026:65442' - url: 'https://access.redhat.com/errata/RHSA-2026:65110' - url: 'https://access.redhat.com/errata/RHSA-2026:65105' - url: 'https://access.redhat.com/errata/RHSA-2026:65669' - url: 'https://access.redhat.com/errata/RHSA-2026:65103' - url: 'https://access.redhat.com/errata/RHSA-2026:65670' - url: 'https://access.redhat.com/errata/RHSA-2026:65158' - url: 'https://access.redhat.com/errata/RHSA-2026:65888' - url: 'https://access.redhat.com/errata/RHSA-2026:65766' tags: - nvd - csaf - vex - red-hat - score-dispute epss: 0.00592 epssPercentile: 0.45941 ingestedAt: '2026-08-22T13:32:36.526Z' scores: nvd: 9.8 vendor: 7.5 --- ## Overview Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. ## Affected - `firefox < 140.14.0` - `firefox >= 141.0.0, < 153.1.0` - `thunderbird < 140.14.0` - `thunderbird >= 141.0, < 153.1.0` ## Remediation Upgrade past the affected range: - `firefox 153.1.0` - `thunderbird 153.1.0` ## Vendor advisories - **RHSA-2026:64813** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:64813) - **RHSA-2026:58899** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58899) - **RHSA-2026:58898** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58898) - **RHSA-2026:65111** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65111) - **RHSA-2026:64814** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:64814) - **RHSA-2026:58897** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58897) - **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8 · updated 2026-09-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74944.json) - **RHSA-2026:65442** · Red Hat · fixed in: Red Hat Enterprise Linux Server (v. 7 ELS) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65442) - **RHSA-2026:65110** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65110) - **RHSA-2026:65105** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65105) - **RHSA-2026:65669** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65669) - **RHSA-2026:65103** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65103) - **RHSA-2026:65670** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65670) - **RHSA-2026:65888** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-09-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:65888) - **RHSA-2026:65766** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-09-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:65766)