PT-2026-41903 · Mozilla · Firefox+1

Q1 · Published 2026-05-19 · Updated 2026-05-27 · CVE-2026-8949

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

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

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 integer overflow exists in the Widget: Win32 component. An integer overflow occurs when an arithmetic operation attempts to create a numeric value that is outside of the range that can be represented with a given number of bits.

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

Fix

Integer Overflow

Weakness Enumeration

CWE-190

Related Identifiers

CVE-2026-8949

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

Thunderbird

References · 77

• https://nvd.nist.gov/vuln/detail/CVE-2026-8947 · Security Note
• https://mozilla.org/en-US/security/advisories/mfsa2026-46/#CVE-2026-8949 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-8970 · Security Note
• https://cve.org/CVERecord?id=CVE-2026-8949 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-8401 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-8949 · Security Note
• https://mozilla.org/en-US/security/advisories/mfsa2026-48/#CVE-2026-8949 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-8956 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-8388 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-8391 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-8958 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-8949 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-8974 · Security Note
• https://mozilla.org/security/advisories/mfsa2026-51 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-8953 · Security Note