Debian Security Advisory

DLA-2759-1 gnutls28 -- LTS security update

Date Reported:
18 Sep 2021
Affected Packages:
Security database references:
In the Debian bugtracking system: Bug 961889.
More information:

GnuTLS, a portable cryptography library, fails to validate alternate trust chains in some conditions. In particular this breaks connecting to servers that use Let's Encrypt certificates, starting 2021-10-01.

For Debian 9 stretch, this problem has been fixed in version 3.5.8-5+deb9u6.

We recommend that you upgrade your gnutls28 packages.

For the detailed security status of gnutls28 please refer to its security tracker page at:

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