The Tails project has released version 7.15.1 of its privacy-focused Linux distribution, which routes internet traffic through the Tor network and leaves no traces on the computer after shutdown.
This emergency update addresses a security issue involving compromised certificates that could allow attackers to impersonate HTTPS-protected websites.
The issue concerns eMudhra, a certificate authority whose intermediate certificates were compromised. On October 17, Mozilla blocked certificates issued by the authority, and Tails has now followed suit to protect its users.
The main concern is that an attacker with one of the compromised intermediate certificates could impersonate legitimate websites, even when HTTPS is enabled.
As you might expect, this matters for Tails users because a malicious Tor exit node, an exit node’s internet service provider, or a government controlling network infrastructure could carry out such an attack.
However, the developers clarify that onion services are not vulnerable to this particular attack. They also state that they have no evidence of Tor exit nodes exploiting the compromised certificates so far.
To address the issue, Tails 7.15.1 updates Tor Browser to version 15.0.26, which fixes CVE-2026-113470 and blocks all certificates issued by eMudhra.
The update also extends protection beyond Tor Browser. Tails uses Debian’s ca-certificates package to manage trusted certificate authorities for other applications, and this package has been updated to block eMudhra certificates system-wide.
Given the security implications, users are strongly encouraged to upgrade. Automatic upgrades to Tails 7.15.1 are available from version 7.0 or later and preserve existing Persistent Storage.
Those unable to complete an automatic upgrade, or whose system fails to start afterward, can perform a manual upgrade instead. Users setting up Tails for the first time can download the latest USB or ISO images from the official website.
For additional details, see the announcement.
One important detail: installing Tails on an existing USB stick instead of upgrading will erase its Persistent Storage, so existing users should follow the upgrade procedure rather than perform a fresh installation.
