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Alerts This Week
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Debian 11: DLA-4239-1 critical: thunderbird security issues

debian lts
Calendar Grey July 11, 2025
Dist Debian Esm H88
To optimize your Thunderbird setup on Debian LTS and address the security flaws outlined in the advisory DLA-4239-1, follow these steps to ensure a robust and secure email experience.
Multiple vulnerabilities have been fixed in the email, calendar and contacts client Thunderbird
Topics%20covered

Topics Covered

security advisory critical debian DoS thunderbird credential leakage

Summary

CVE-2025-5986

Unsolicited File Download, Disk Space Exhaustion, and
Credential Leakage via mailbox:/// Links

CVE-2025-6424

Use-after-free in FontFaceSet

CVE-2025-6425

The WebCompat WebExtension shipped exposed a persistent UUID

CVE-2025-6429

Incorrect parsing of URLs could have allowed embedding of youtube.com

CVE-2025-6430

Content-Disposition header ignored when a file is included
in an embed or object tag

For Debian 11 bullseye, these problems have been fixed in version
1:128.12.0esr-1~deb11u1.

We recommend that you upgrade your thunderbird packages.

For the detailed security status of thunderbird please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/thunderbird

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS


Severity
critical
Lowest
Low
Medium
High
Critical

Package: thunderbird
Version: 1:128.12.0esr-1~deb11u1
CVE ID: CVE-2025-5986 CVE-2025-6424 CVE-2025-6425 CVE-2025-6429

Topics%20covered

Topics Covered

security advisory critical debian DoS thunderbird credential leakage

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