Cyber Resilience

CVE-2025-1935

Medium

Published: 04 March 2025

Published
04 March 2025
Modified
13 April 2026
KEV Added
Patch
CVSS Score v3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS Score 0.0023 45.6th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-1935 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Mozilla Firefox. Its CVSS base score is 4.3 (Medium).

Operationally, ranked at the 45.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A web page could trick a user into setting that site as the default handler for a custom URL protocol. This vulnerability was fixed in Firefox 136, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

mozilla
firefox
≤ 128.8.0 · ≤ 136.0
mozilla
thunderbird
≤ 128.8.0 · 129.0 — 136.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References