CVE-2026-6786
Memory safety bugs fixed in Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150
- State
- Published
- Severity
- 7.5 High
- Published
- Apr 21, 2026
- Updated
- Jul 15, 2026
- Reserved
- Apr 21, 2026
Description
Memory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H | CISA-ADP |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H | redhat-SADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
FirefoxMozilla |
|
ThunderbirdMozilla |
|
References
- Memory safety bugs fixed in Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150
- https://www.mozilla.org/security/advisories/mfsa2026-30/
- https://www.mozilla.org/security/advisories/mfsa2026-32/
- https://www.mozilla.org/security/advisories/mfsa2026-33/
- https://www.mozilla.org/security/advisories/mfsa2026-34/
- https://access.redhat.com/security/cve/CVE-2026-6786vdb-entry
- RHBZ#2460088issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6786.json
- https://access.redhat.com/errata/RHSA-2026:19704vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:17690vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19463vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:10767vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:12285vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19041vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19131vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:10766vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:13537vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19655vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19465vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19542vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19466vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:17477vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19467vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:17687vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19468vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:17689vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19461vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19464vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19469vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:17688vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19462vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:10757vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:15892vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19201vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19348vendor-advisory
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