Cyber Resilience

CVE-2025-3932

Medium

Published: 14 May 2025

Published
14 May 2025
Modified
13 April 2026
KEV Added
Patch
CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS Score 0.0028 51.9th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-3932 is a medium-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Mozilla Thunderbird. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 48.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

It was possible to craft an email that showed a tracking link as an attachment. If the user attempted to open the attachment, Thunderbird automatically accessed the link. The configuration to block remote content did not prevent that. Thunderbird has…

more

been fixed to no longer allow access to web pages listed in the X-Mozilla-External-Attachment-URL header of an email. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.

CWE(s)

Related Threats

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

Affected Assets

mozilla
thunderbird
≤ 128.10.1 · 129.0 — 138.0.1

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-288

Authorizing remote access reduces the ability to bypass authentication via unauthorized alternate remote channels.

addresses: CWE-288

Users can identify logons via alternate paths or channels by reviewing the previous logon time.

addresses: CWE-288

Adaptive requirements can apply across access paths, reducing the ability to bypass authentication via alternate channels or paths.

addresses: CWE-288

Centralized IdPs close alternate authentication paths that enable bypass.

addresses: CWE-288

Enforces authentication for non-organizational users, making it harder to bypass via alternate paths or channels.

addresses: CWE-288

Requires authentication to occur exclusively over the isolated trusted path, directly preventing bypass via alternate or untrusted channels.

References