Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Critical CVSS 9.8
Summary
Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
In-depth triage · Auto channel
No in-depth report has been generated yet (DR-003 v2 AI pipeline is under construction).
Affected products
- :
Sources
- NVD DATABASE
Original Links
- https://bugzilla.mozilla.org/show_bug.cgi?id=2017512 Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-20/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-21/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-22/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-23/
- https://www.mozilla.org/security/advisories/mfsa2026-24/
- https://access.redhat.com/errata/RHSA-2026:5930
- https://access.redhat.com/errata/RHSA-2026:5931
- https://access.redhat.com/errata/RHSA-2026:5932
- https://access.redhat.com/errata/RHSA-2026:6188
- https://access.redhat.com/errata/RHSA-2026:6342
- https://access.redhat.com/errata/RHSA-2026:6917
- https://access.redhat.com/errata/RHSA-2026:7837
- https://access.redhat.com/errata/RHSA-2026:7838
- https://access.redhat.com/errata/RHSA-2026:7839
- https://access.redhat.com/errata/RHSA-2026:7840
- https://access.redhat.com/errata/RHSA-2026:7841
- https://access.redhat.com/errata/RHSA-2026:7842
- https://access.redhat.com/errata/RHSA-2026:7843
- https://access.redhat.com/errata/RHSA-2026:7845
- https://access.redhat.com/errata/RHSA-2026:7858
- https://access.redhat.com/errata/RHSA-2026:8284
- https://access.redhat.com/errata/RHSA-2026:8285
- https://access.redhat.com/errata/RHSA-2026:8286
- https://access.redhat.com/errata/RHSA-2026:8287
- https://access.redhat.com/errata/RHSA-2026:8288
- https://access.redhat.com/errata/RHSA-2026:8289
- https://access.redhat.com/errata/RHSA-2026:8290
- https://access.redhat.com/errata/RHSA-2026:8315
- https://access.redhat.com/errata/RHSA-2026:8427
- https://access.redhat.com/errata/RHSA-2026:8850
- https://access.redhat.com/security/cve/CVE-2026-4691
- https://bugzilla.redhat.com/show_bug.cgi?id=2450738
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4691.json
Timeline
- nvd_ingest NVD