CVE-2025-3932: mozilla thunderbird
Vulnerability summary
CVE-2025-3932 is a medium (CVSS 6.5) vulnerability in mozilla thunderbird. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.5% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 17 · Related 4Timeline
- 14-05-2025PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
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 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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.39%
Chance of exploitation in the next 30 days
Percentile
32%
Versus all other CVEs
30-day change
+0.02 pp
From 0.37% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- thunderbird< 1:128.10.1esr-1~deb12u1 | < 1:128.10.1esr-1
Mozilla1 product
- thunderbird< 128.10.1 | ≥ 129.0, < 138.0.1
Ubuntu1 product
- thunderbird< 1:128.12.0+build1-0ubuntu0.22.04.1
3 vendors · 3 products
