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Fencer Vulns
medium 6.5

CVE-2025-3932 json

Tracking Links in Attachments Bypassed Remote Content Blocking

published 2025-05-14 17 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-14934

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits
0
none known

Summary

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.

Patch / fix

  • mozilla thunderbird 128.10.1, 138.0.1
  • mozilla thunderbird_esr 128.10.1, 138.0.1
  • thunderbird Debian 12 1:128.10.1esr-1~deb12u1
  • thunderbird Debian 14, Debian 13 1:128.10.1esr-1

debian advisories DEBIAN-CVE-2025-3932

  • thunderbird Ubuntu 22.04 LTS 1:128.12.0+build1-0ubuntu0.22.04.1

ubuntu advisories UBUNTU-CVE-2025-3932

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • thunderbird RHEL 8 128.11.0-1.el8_10
  • thunderbird RHEL 9 128.10.1-1.el9_6
  • thunderbird RHEL 10.0 128.10.1-1.el10_0
  • thunderbird RHEL 8.8 TUS, RHEL 8.8 E4S 128.10.1-1.el8_8
  • thunderbird RHEL 8.6 TUS, RHEL 8.6 E4S, RHEL 8.6 AUS 128.10.1-1.el8_6
  • thunderbird RHEL 8.4 AUS 128.10.1-1.el8_4
  • thunderbird RHEL 8.2 AUS 128.10.1-1.el8_2
  • thunderbird RHEL 9.2 EUS 128.10.1-1.el9_2

red hat advisories RHSA-2025:8756RHSA-2025:8784RHSA-2025:8594RHSA-2025:8507RHSA-2025:8391RHSA-2025:8326

  • MozillaThunderbird SLE Workstation Extension 15 SP7, SLE Workstation Extension 15 SP6, SLE Module for Package Hub 15 SP7 +2 more 128.10.1-150200.8.215.1

suse advisories SUSE-SU-2025:01660-2SUSE-SU-2025:01660-1

  • MozillaThunderbird openSUSE Tumbleweed 128.10.1-1.1

opensuse advisories openSUSE-SU-2025:15131-1

  • thunderbird AlmaLinux 8 128.11.0-1.el8_10.alma.1
  • thunderbird AlmaLinux 10 128.10.1-1.el10_0.alma.1

almalinux advisories ALSA-2025:8756ALSA-2025:8196

  • thunderbird Rocky Linux 9 128.10.1-1.el9_6
  • thunderbird Rocky Linux 10 128.10.1-1.el10_0
  • thunderbird Rocky Linux 8 128.11.0-1.el8_10

rocky linux advisories RLSA-2025:8203RLSA-2025:8196RLSA-2025:8756

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-3932 updated cvss 6.5

thunderbird: Tracking Links in Attachments Bypassed Remote Content Blocking

  • Red Hat Enterprise Linux 6 thunderbird Red Hat Enterprise Linux 7 thunderbird
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 10 thunderbird-flatpak
    affected: no fix available
  • Red Hat Enterprise Linux AppStream (v. 8) thunderbird 128.11.0-1.el8_10
    fixed: vendor fix RHSA-2025:8756
  • Red Hat Enterprise Linux AppStream (v. 9) thunderbird 128.10.1-1.el9_6
    fixed: vendor fix RHSA-2025:8203
  • Red Hat Enterprise Linux AppStream (v. 10) thunderbird 128.10.1-1.el10_0
    fixed: vendor fix RHSA-2025:8196
  • Red Hat Enterprise Linux AppStream AUS (v. 8.2) thunderbird 128.10.1-1.el8_2
    fixed: vendor fix RHSA-2025:8391
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird 128.10.1-1.el8_4
    fixed: vendor fix RHSA-2025:8507
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird 128.10.1-1.el8_6 Red Hat Enterprise Linux AppStream E4S (v.8.6) thunderbird 128.10.1-1.el8_6
    fixed: vendor fix RHSA-2025:8594
show 6 more
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) thunderbird 128.10.1-1.el8_8
    fixed: vendor fix RHSA-2025:8784
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) thunderbird 128.10.1-1.el9_0
    fixed: vendor fix RHSA-2025:8324
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) thunderbird 128.10.1-1.el9_2
    fixed: vendor fix RHSA-2025:8326
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) thunderbird 128.10.1-1.el9_4
    fixed: vendor fix RHSA-2025:8325
  • Red Hat Enterprise Linux AppStream TUS (v.8.6) thunderbird 128.10.1-1.el8_6
    fixed: vendor fix RHSA-2025:8594
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) thunderbird 128.10.1-1.el8_8
    fixed: vendor fix RHSA-2025:8784

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products

  • Mozilla Thunderbird

Classification

Weakness
  • CWE-288 Authentication Bypass Using an Alternate Path or Channel

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.