Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable yes

Technical Impact total

Affected Vendors & Products

Vendors Products
Mozilla
  • Firefox
  • Thunderbird

Configuration 1 [-]

OR cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

No data.

References
Link Providers
https://bugzilla.mozilla.org/show_bug.cgi?id=2054842 cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-74940 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-74940 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-74/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-75/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-76/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-76/#CVE-2026-74940 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-77/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-78/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-79/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-79/#CVE-2026-74940 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-80/ cve-icon cve-icon
History

Fri, 21 Aug 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Fri, 21 Aug 2026 11:00:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*

Thu, 20 Aug 2026 20:45:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla thunderbird
Weaknesses CWE-416
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
Vendors & Products Mozilla thunderbird
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}

 cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Wed, 19 Aug 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-825
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}

threat_severity

Important

Tue, 18 Aug 2026 23:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Tue, 18 Aug 2026 19:00:00 +0000

Type Values Removed Values Added
Description Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
References

Tue, 18 Aug 2026 15:30:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox

Tue, 18 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Tue, 18 Aug 2026 12:45:00 +0000

Type Values Removed Values Added
Description Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
Title Use-after-free in the Graphics: Text component
References
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2026-08-18T12:23:28.488Z

Updated: 2026-08-21T20:12:37.811Z

Reserved: 2026-08-17T11:57:37.997Z

Link: CVE-2026-74940

cve-icon Vulnrichment

Updated: 2026-08-21T20:12:26.068Z

cve-icon NVD

Status : Modified

Published: 2026-08-18T13:17:30.370

Modified: 2026-08-21T21:17:05.457

Link: CVE-2026-74940

cve-icon Redhat

Severity : Important

Publid Date: 2026-08-18T12:23:28Z

Links: CVE-2026-74940 - Bugzilla