PT-2026-41912 · Mozilla+1 · Firefox+2

Yaqoub Aldurayhim · Published 2026-05-19 · Updated 2026-06-02 · CVE-2026-8958

Positive Technologies (AI Summary)

CVSS v3.1

8.6

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 151 Firefox ESR versions prior to 140.11 Thunderbird versions prior to 151 Thunderbird versions prior to 140.11

Description An issue in the Security: Process Sandboxing component allows for information disclosure and sandbox escape. A sandbox is a security mechanism for separating running programs, ensuring that code in one process cannot access memory or resources of another.

Recommendations Update to version 151 Update to version 140.11 Update to version 151 Update to version 140.11

Fix

DoS

Protection Mechanism Failure

Exposure of Resource to Wrong Sphere

Weakness Enumeration

CWE-693

CWE-668

Related Identifiers

ALSA-2026:21378

ALSA-2026:21380

ALSA-2026:21381

ALSA-2026:21382

ALSA-2026:22325

ALSA-2026:22643

CVE-2026-8958

OESA-2026-2392

OESA-2026-2393

OESA-2026-2394

OPENSUSE-SU-2026:10813-1

OPENSUSE-SU-2026:10863-1

OPENSUSE-SU-2026:10864-1

Affected Products

Firefox

Rocky Linux

Thunderbird

References · 140

• https://nvd.nist.gov/vuln/detail/CVE-2026-8391 · Security Note
• https://errata.almalinux.org/8/ALSA-2026-22643.html · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-46 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-8958 · Vendor Advisory
• https://errata.rockylinux.org/RLSA-2026:21378 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2026-51/#CVE-2026-8958 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-8959 · Security Note
• https://errata.rockylinux.org/RLSA-2026:21382 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2026-46/#CVE-2026-8958 · Vendor Advisory
• https://errata.almalinux.org/10/ALSA-2026-21380.html · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2026-21382.html · Vendor Advisory
• https://osv.dev/vulnerability/OESA-2026-2392 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2026-48/#CVE-2026-8958 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-48/#CVE-2026-8958 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-51/#CVE-2026-8958 · Vendor Advisory