CVE-2025-3875

Name: CVE-2025-3875
Creator: NVD / NIST
Published: 2025-05-14T17:15:48.47+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.32%

Last modified Jun 17, 2026

CVE-2025-3875 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an (invalid) value "Spoofed Name ", Thunderbird treats spoofed@example.com as the actual address. EPSS estimates a 0.32% chance of exploitation in the next 30 days.

Description

Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an (invalid) value "Spoofed Name ", Thunderbird treats spoofed@example.com as the actual address. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

0.32%

23.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-290

Affected Software

Vendor	Product	Versions
Mozilla	Thunderbird	< 128.10.0
Mozilla	Thunderbird	>= 129.0, < 138.0.1

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1950629Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-34/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-35/Vendor Advisory
https://lists.debian.org/debian-lts-announce/2025/05/msg00022.html

Timeline

Published: May 14, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-3875?

How severe is CVE-2025-3875?

CVE-2025-3875 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.

How do I fix CVE-2025-3875?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-3875?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST