PT-2026-49660 · Mozilla+1 · Firefox+2

Zijie Zhao · CVE-2026-12291 · Published 2026-06-16 · Updated 2026-07-10

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 152 Firefox ESR versions prior to 140.12 Firefox ESR versions prior to 115.37 Thunderbird versions prior to 152 Thunderbird versions prior to 140.12

Description A use-after-free issue exists in the Networking: HTTP component. Use-after-free occurs when an application continues to use a pointer after it has been freed, which can lead to crashes or arbitrary code execution.

Recommendations Update Firefox to version 152. Update Firefox ESR to version 140.12. Update Firefox ESR to version 115.37. Update Thunderbird to version 152. Update Thunderbird to version 140.12.

Fix

DoS

Use After Free

Weakness Enumeration

CWE-825

CWE-416

Related Identifiers

ALSA-2026:27717

ALSA-2026:27733

ALSA-2026:27734

ALSA-2026:29940

ALSA-2026:30846

ALSA-2026:33445

CVE-2026-12291

OESA-2026-2735

OPENSUSE-SU-2026:11052-1

OPENSUSE-SU-2026:11055-1

OPENSUSE-SU-2026:11072-1

OPENSUSE-SU-2026:21043-1

OPENSUSE-SU-2026:21168-1

RHSA-2026:33445

SUSE-SU-2026:22351-1

SUSE-SU-2026:2582-1

SUSE-SU-2026:2583-1

SUSE-SU-2026:2814-1

SUSE-SU-2026:2852-1

Affected Products

Firefox

Rocky Linux

Thunderbird

References · 247

• https://osv.dev/vulnerability/SUSE-SU-2026:22351-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-12315 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-12325 · Security Note
• https://mozilla.org/en-US/security/advisories/mfsa2026-58 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-12291 · Security Note
• https://osv.dev/vulnerability/openSUSE-SU-2026:11055-1 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:27733 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:11052-1 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2026-61/#CVE-2026-12291 · Vendor Advisory
• https://osv.dev/vulnerability/ALSA-2026:27717 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:39428 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-12289 · Security Note
• https://osv.dev/vulnerability/openSUSE-SU-2026:21168-1 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:39142 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-12329 · Security Note