Spoofing attack in Mozilla Thunderbird - CVE-2025-3523

Vulnerability identifier: #VU107465

CSH Severity: Low

CVSS v4: 2.1 [CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N]

CVE-ID: CVE-2025-3523

CWE-ID: CWE-451

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform spoofing attack.

When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct link is used on click, the misleading hover text could trick users into downloading content from untrusted sources.

Mozilla Thunderbird
Debian Linux
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Workstation Extension 15
Anolis OS
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Slackware Linux
SUSE Package Hub 15
openSUSE Leap
Ubuntu
openEuler
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
thunderbird
mozilla-thunderbird
thunderbird (Red Hat package)
MozillaThunderbird-debuginfo
MozillaThunderbird
MozillaThunderbird-debugsource
MozillaThunderbird-translations-other
MozillaThunderbird-translations-common
thunderbird (Debian package)
thunderbird-debuginfo
thunderbird-debugsource
thunderbird-librnp-rnp
thunderbird-wayland
thunderbird (Ubuntu package)

Install updates from vendor's website.

Mozilla Thunderbird - addressed in versions 128.9.2, 137.0.2
thunderbird - update to 128.9.0-2.0.1
mozilla-thunderbird - update to 128.9.2esr
thunderbird (Red Hat package) - addressed in versions 128.9.2-1.el8_2, 128.9.2-1.el8_4, 128.9.2-1.el8_6, 128.9.2-1.el8_8, 128.9.2-1.el8_10, 128.9.2-1.el9_0, 128.9.2-1.el9_2, 128.9.2-1.el9_4, 128.9.2-1.el9_5
MozillaThunderbird-debuginfo - update to 128.9.2-150200.8.209.1
MozillaThunderbird - update to 128.9.2-150200.8.209.1
MozillaThunderbird-debugsource - update to 128.9.2-150200.8.209.1
MozillaThunderbird-translations-other - update to 128.9.2-150200.8.209.1
MozillaThunderbird-translations-common - update to 128.9.2-150200.8.209.1
thunderbird (Debian package) - update to 1:128.10.0esr-1~deb12u1
thunderbird - update to 128.11.1-1
thunderbird-debuginfo - update to 128.11.1-1
thunderbird-debugsource - update to 128.11.1-1
thunderbird-librnp-rnp - update to 128.11.1-1
thunderbird-wayland - update to 128.11.1-1
thunderbird (Ubuntu package) - update to 1:128.12.0+build1-0ubuntu0.22.04.1

• https://www.mozilla.org/en-US/security/advisories/mfsa2025-27/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1958385
• https://www.mozilla.org/en-US/security/advisories/mfsa2025-26/

• Multiple vulnerabilities in Mozilla Thunderbird and Thunderbird ESR
• Slackware Linux update for mozilla-thunderbird
• SUSE update for MozillaThunderbird
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Debian update for thunderbird
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Anolis OS update for thunderbird
• openEuler 24.03 LTS SP2 update for thunderbird
• Ubuntu update for thunderbird