Cyber Resilience

CVE-2025-14327

Auth Bypass in Mozilla Firefox ≤ 146.0

Published
09 December 2025
Modified
13 April 2026
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0036 29th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2025-14327 is a high-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Mozilla Firefox. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 29th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-2 (Flaw Remediation) and CM-6 (Configuration Settings) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Spoofing issue in the Downloads Panel component. This vulnerability was fixed in Firefox 146, Thunderbird 146, Firefox ESR 140.7, and Thunderbird 140.7.

CWE(s)

Related Threats

CVEs Like This One

CVE-2026-0890Same product: Mozilla Firefox
CVE-2024-10465Same product: Mozilla Firefox
CVE-2026-6762Same product: Mozilla Firefox
CVE-2024-10462Same product: Mozilla Firefox
CVE-2026-8960Same product: Mozilla Firefox
CVE-2026-8961Same product: Mozilla Firefox
CVE-2025-3029Same product: Mozilla Firefox
CVE-2026-8963Same product: Mozilla Firefox
CVE-2026-2800Same product: Mozilla Firefox
CVE-2026-4728Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 146.0
mozilla
thunderbird
≤ 146.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • CM-6 Configuration Settings
Detect
Catch it (NIST detect / respond)
  • SI-7 Software, Firmware, and Information Integrity
Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V10.4.16
  • V10.5.1
  • V11.4.3

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires timely application of the vendor patch that eliminates the Downloads Panel spoofing flaw (CWE-290).

detect

Requires verification of software/firmware integrity, which can detect unauthorized modifications that enable spoofed download UI elements.

prevent

Enforces configuration settings that restrict or harden browser features, limiting exposure to the spoofing vector until patched.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-04 full match
prevents

Protecting, conveying, and verifying identity assertions specifically prevents the spoofing that enables authentication bypass.

PR.AA-03 mostly match
prevents

Requiring authentication of users/services/hardware directly counters spoofing-based bypass when strong methods are used.

PR.AA-02 partial match
prevents

Proofing and binding identities reduces spoofing opportunities during enrollment but does not address runtime authentication implementation flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

degrades

Secure authentication control directly mitigates authentication bypass by spoofing.

degrades

Authentication information management directly addresses credential handling that prevents spoofing.

detects

Security testing can detect spoofing vulnerabilities but does not prevent them by itself.

prevents

Access control policy reduces spoofing opportunities but does not prescribe authentication mechanisms.

prevents

Identity management supports unique identities but does not guarantee resistance to spoofing.

prevents

Access rights assignment limits exposure but does not enforce authentication strength.

References