Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

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 Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact total

Affected Vendors & Products

Vendors Products
Mozilla
  • Firefox

No data.

No data.

References
Link Providers
https://bugzilla.mozilla.org/show_bug.cgi?id=2036929 cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-12291 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-12291 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-57/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-58/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-58/#CVE-2026-12291 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-59/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-60/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-61/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-61/#CVE-2026-12291 cve-icon
History

Thu, 18 Jun 2026 19:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE‑416

Thu, 18 Jun 2026 17:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
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'}

 ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Thu, 18 Jun 2026 16:45:00 +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

Thu, 18 Jun 2026 04:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE‑416

Tue, 16 Jun 2026 16:45:00 +0000

Type Values Removed Values Added
Description Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
References

Tue, 16 Jun 2026 14:45:00 +0000

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

Tue, 16 Jun 2026 13:15:00 +0000

Type Values Removed Values Added
Description Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37.
Title Use-after-free in the Networking: HTTP component
References
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2026-06-16T11:52:24.990Z

Updated: 2026-06-18T16:11:30.479Z

Reserved: 2026-06-15T15:08:06.495Z

Link: CVE-2026-12291

cve-icon Vulnrichment

Updated: 2026-06-18T14:28:49.254Z

cve-icon NVD

Status : Undergoing Analysis

Published: 2026-06-16T13:16:29.363

Modified: 2026-06-16T17:16:32.983

Link: CVE-2026-12291

cve-icon Redhat

Severity : Important

Publid Date: 2026-06-16T11:52:24Z

Links: CVE-2026-12291 - Bugzilla