PT-2025-26730 · Mozilla+5 · Firefox+5

Simon · Published 2025-06-24 · Updated 2026-02-02 · CVE-2025-6433

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions: Firefox versions prior to 140

Description: The issue arises when a user visits a webpage with an invalid TLS certificate and grants an exception. In this scenario, the webpage can provide a WebAuthn challenge that the user is prompted to complete, violating the WebAuthn specification that requires a secure transport established without errors.

Recommendations: For Firefox versions prior to 140, update to version 140 or later to resolve the issue. As a temporary workaround, consider avoiding exceptions for invalid TLS certificates to minimize the risk of exploitation. Restrict access to WebAuthn challenges on webpages with invalid TLS certificates until the issue is resolved.

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

ALT-PU-2025-11100

ALT-PU-2025-11495

ALT-PU-2025-11497

ALT-PU-2025-14599

ALT-PU-2025-8725

ALT-PU-2025-9988

BDU:2025-07649

CVE-2025-6433

OPENSUSE-SU-2025:15325-1

OPENSUSE-SU-2025:15371-1

OPENSUSE-SU-2025:15383-1

SUSE-SU-2025:02339-1

SUSE-SU-2025:02529-1

SUSE-SU-2025:02546-1

SUSE-SU-2025_02339-1

SUSE-SU-2025_02529-1

USN-7991-1

Affected Products

Alt Linux

Astra Linux

Firefox

Linuxmint

Suse

Ubuntu

References · 177

• https://ubuntu.com/security/CVE-2025-13015 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-0887 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-11711 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2025-51 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-0891 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2025-54 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2025-51 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-14328 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2025:02339-1 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2025:15383-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-8039 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2025:02529-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-11715 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-8038 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-6434 · Vendor Advisory