Cyber Resilience

CVE-2025-8043

Mozilla Firefox ≤ 141.0

Public PoC
Published
22 July 2025
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0037 30th percentile
Risk Priority 71 floored blend · peak EPSS

Summary

CVE-2025-8043 is a critical-severity User Interface (UI) Misrepresentation of Critical Information (CWE-451) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Phishing (T1566); ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-8043 is a vulnerability in Firefox where Focus incorrectly truncated URLs towards the beginning instead of around the origin, leading to potential user interface misrepresentation of critical information (CWE-451). This issue affects Firefox users prior to version 141 and carries a critical CVSS score of 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). The vulnerability was published on 2025-07-22T21:15:51.263.

Remote attackers can exploit this vulnerability over the network with low attack complexity, requiring no privileges or user interaction. Exploitation enables high-impact consequences across confidentiality, integrity, and availability, such as misleading users about the true destination or nature of URLs through improper truncation.

Mozilla addressed this vulnerability with a fix in Firefox 141. Additional details are available in the Mozilla Foundation Security Advisory (MFSA 2025-56) at https://www.mozilla.org/security/advisories/mfsa2025-56/ and the corresponding Bugzilla entry at https://bugzilla.mozilla.org/show_bug.cgi?id=1970209.

OWASP Top 10 for Web (2025)

A06:2025 Insecure Design

EU & UK References

Vulnerability Data

Focus incorrectly truncated URLs towards the beginning instead of around the origin. This vulnerability was fixed in Firefox 141.

CWE(s)
CWE-451

Related Threats

MITRE ATT&CK Enterprise Techniques

T1566 Phishing Initial Access
Adversaries may send phishing messages to gain access to victim systems.
attack.mitre.org →
T1566.002 Spearphishing Link Initial Access
Adversaries may send spearphishing emails with a malicious link in an attempt to gain access to victim systems.
attack.mitre.org →
T1566.003 Spearphishing via Service Initial Access
Adversaries may send spearphishing messages via third-party services in an attempt to gain access to victim systems.
attack.mitre.org →
T1598 Phishing for Information Reconnaissance
Adversaries may send phishing messages to elicit sensitive information that can be used during targeting.
attack.mitre.org →
T1598.003 Spearphishing Link Reconnaissance
Adversaries may send spearphishing messages with a malicious link to elicit sensitive information that can be used during targeting.
attack.mitre.org →
T1534 Internal Spearphishing Lateral Movement
After they already have access to accounts or systems within the environment, adversaries may use internal spearphishing to gain access to additional information or compromise other users within the same organization.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-16403Same product: Mozilla Firefox
CVE-2026-8964Same product: Mozilla Firefox
CVE-2025-4086Same product: Mozilla Firefox
CVE-2024-6610Same product: Mozilla Firefox
CVE-2024-7529Same product: Mozilla Firefox
CVE-2026-3889Same product: Mozilla Thunderbird
CVE-2025-9183Same product: Mozilla Firefox
CVE-2026-2634Same product: Mozilla Firefox
CVE-2025-3523Same product: Mozilla Thunderbird
CVE-2026-2032Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 141.0
mozilla
thunderbird
≤ 141.0

Mitigating Controls

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.PS-06 mostly match
prevents

Secure SDLC practices directly address design and implementation of accurate, non-spoofable UI elements.

PR.AT-01 partial match
prevents

User awareness training helps people recognize and avoid harm from UI misrepresentation such as phishing, but does not prevent the flaw itself.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect UI misrepresentation vulnerabilities before deployment.

A.6.3 Information security awareness, education and training partial match
prevents

Security awareness training can teach users to recognize UI misrepresentation and phishing attempts.

A.8.23 Web filtering partial match
mitigates

Web filtering can block known phishing sites that exploit UI misrepresentation.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle includes UI/UX security requirements that can prevent misrepresentation of critical information.

A.8.26 Application security requirements partial match
prevents

Application security requirements can mandate proper display and validation of critical information in the UI.

A.8.28 Secure coding partial match
prevents

Secure coding practices can prevent UI flaws that obscure or spoof critical information.

References