Cyber Resilience

CVE-2025-1940

Mozilla Firefox ≤ 136.0

Published
04 March 2025
Modified
13 April 2026
Patch / advisory
CVSS Score v3.1 7.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
EPSS Score 0.0024 15th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2025-1940 is a high-severity Improper Restriction of Rendered UI Layers or Frames (CWE-1021) vulnerability in Mozilla Firefox. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

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-2025-1940 is a user interface vulnerability affecting only Android versions of Firefox, where a select option could partially obscure the confirmation prompt displayed before launching external applications. This flaw enables tricking users into unexpectedly launching an external app. Published on 2025-03-04, it is linked to CWE-1021 and carries a CVSS v3.1 base score of 7.1 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N).

A remote attacker with no privileges can exploit this over the network with low attack complexity by crafting content that positions a select element to hide critical parts of the confirmation dialog. Exploitation requires user interaction, such as the victim confirming an action they do not fully perceive. Success leads to the unintended launch of an external app, resulting in high confidentiality impact and low integrity impact.

Mozilla fixed this vulnerability in Firefox 136. Mitigation details are available in the Mozilla Foundation Security Advisory MFSA 2025-14 at https://www.mozilla.org/security/advisories/mfsa2025-14/ and the related Bugzilla entry at https://bugzilla.mozilla.org/show_bug.cgi?id=1908488.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A select option could partially obscure the confirmation prompt shown before launching external apps. This could be used to trick a user in to launching an external app unexpectedly. *This issue only affects Android versions of Firefox.*. This vulnerability was…

more

fixed in Firefox 136.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
T1056 Input Capture Collection
Adversaries may use methods of capturing user input to obtain credentials or collect information.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-2613Same product: Mozilla Firefox
CVE-2025-6434Same product: Mozilla Firefox
CVE-2024-7523Same product: Mozilla Firefox
CVE-2023-6211Same product: Mozilla Firefox
CVE-2026-16397Same product: Mozilla Firefox
CVE-2024-10004Same product: Mozilla Firefox
CVE-2025-5267Same product: Mozilla Firefox
CVE-2023-25748Same product: Mozilla Firefox
CVE-2024-53976Same product: Mozilla Firefox
CVE-2023-37455Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 136.0

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 require implementing frame-ancestors / X-Frame-Options controls that prevent this weakness.

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.

finds

Security testing can detect missing frame protections, but does not itself implement the control.

degrades

Web filtering can block or sandbox untrusted frames, but does not enforce application-level frame-busting or CSP.

prevents

Application security requirements can mandate frame-ancestors / X-Frame-Options, directly addressing UI redressing risks.

prevents

Secure architecture principles include isolation of UI layers and proper use of browser security controls.

prevents

Secure coding practices directly require implementation of frame-busting headers or CSP frame-ancestors directives.

References