CVE-2025-6434

MEDIUM EPSS 13.6%
Published Jun 24, 20251y ago · Modified Jun 17, 20261w ago
4.3 CVSS 3.1
Medium
Find Similar
Published Jun 24, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

Description

The exception page for the HTTPS-Only feature, displayed when a website is opened via HTTP, lacked an anti-clickjacking delay, potentially allowing an attacker to trick a user into granting an exception and loading a webpage over HTTP. This vulnerability was fixed in Firefox 140 and Thunderbird 140.

CVSS Details

Base Score
4.3
Exploitability
2.8
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Unchanged
Confidentiality None
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
13.6% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-1021

Affected Products 1

VendorProductVersionRange
mozillafirefox* <140.0

References 3

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1955182
    Permissions Required
  • mozilla.org https://www.mozilla.org/security/advisories/mfsa2025-51/
    Vendor Advisory
  • mozilla.org https://www.mozilla.org/security/advisories/mfsa2025-54/

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.