Cyber Resilience

CVE-2025-4087

Medium

Published: 29 April 2025

Published
29 April 2025
Modified
13 April 2026
KEV Added
Patch
CVSS Score v3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.0030 54.1th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-4087 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Mozilla Firefox. Its CVSS base score is 4.8 (Medium).

Operationally, ranked in the top 45.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A vulnerability was identified in Thunderbird where XPath parsing could trigger undefined behavior due to missing null checks during attribute access. This could lead to out-of-bounds read access and potentially, memory corruption. This vulnerability was fixed in Firefox 138, Firefox…

more

ESR 128.10, Thunderbird 138, and Thunderbird 128.10.

CWE(s)

Related Threats

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

Affected Assets

mozilla
firefox
≤ 128.10 · ≤ 138.0
mozilla
thunderbird
≤ 128.10.0 · ≤ 138.0

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References