CVE-2026-4691
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Mozilla | Firefox | 115.34 <= 115.* | unaffected |
| Mozilla | Firefox | 140.9 <= 140.* | unaffected |
| Mozilla | Firefox | 149 <= * | unaffected |
| Mozilla | Thunderbird | 140.9 <= 140.* | unaffected |
| Mozilla | Thunderbird | 149 <= * | unaffected |
Weaknesses
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: yes
- Technical Impact: total
firefox: thunderbird: Use-after-free in the CSS Parsing and Computation component
Additional References
- 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
- https://access.redhat.com/errata/RHSA-2026:8427
- https://access.redhat.com/errata/RHSA-2026:7843
- https://access.redhat.com/errata/RHSA-2026:8315
- https://access.redhat.com/errata/RHSA-2026:5931
- https://access.redhat.com/errata/RHSA-2026:6342
- https://access.redhat.com/errata/RHSA-2026:5932
- https://access.redhat.com/errata/RHSA-2026:6917
- https://access.redhat.com/errata/RHSA-2026:7840
- https://access.redhat.com/errata/RHSA-2026:8285
- https://access.redhat.com/errata/RHSA-2026:7858
- https://access.redhat.com/errata/RHSA-2026:8850
- https://access.redhat.com/errata/RHSA-2026:7842
- https://access.redhat.com/errata/RHSA-2026:8289
- https://access.redhat.com/errata/RHSA-2026:7838
- https://access.redhat.com/errata/RHSA-2026:8288
- https://access.redhat.com/errata/RHSA-2026:7839
- https://access.redhat.com/errata/RHSA-2026:8286
- https://access.redhat.com/errata/RHSA-2026:7841
- https://access.redhat.com/errata/RHSA-2026:8287
- https://access.redhat.com/errata/RHSA-2026:7845
- https://access.redhat.com/errata/RHSA-2026:8290
- https://access.redhat.com/errata/RHSA-2026:7837
- https://access.redhat.com/errata/RHSA-2026:8284
- https://access.redhat.com/errata/RHSA-2026:5930
- https://access.redhat.com/errata/RHSA-2026:6188
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2017512
- https://www.mozilla.org/security/advisories/mfsa2026-20/
- https://www.mozilla.org/security/advisories/mfsa2026-21/
- https://www.mozilla.org/security/advisories/mfsa2026-22/
- https://www.mozilla.org/security/advisories/mfsa2026-23/
- https://www.mozilla.org/security/advisories/mfsa2026-24/
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