Ubuntu USN · USN-8190-2

Rack::Session vulnerability

Published: Tue, 28 Apr 2026 13:51

CVE-2026-39324

Summary

Rack::Session could allow unintended access to network services.

Details

USN-8190-1 fixed a vulnerability in Rack::Session. This update provides the corresponding update for Ubuntu 26.04 LTS. Original advisory details: SeungMyung Lee discovered that Rack::Session did not properly reject cookies upon decryption failure. A remote attacker could use this issue to manipulate session contents and possibly gain unauthorized access.

Recommended actions per Ubuntu release

StackPatch playbook auto-generated per release codename and per affected package.

Ubuntu resolute

ruby-rack-session→2.1.1-0.1ubuntu0.26.04.1apt_upgrade
Standard apt upgrade. Install 2.1.1-0.1ubuntu0.26.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y ruby-rack-session
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
ruby-rack-session→2.1.1-0.1ubuntu0.26.04.1apt_upgrade
Standard apt upgrade. Install 2.1.1-0.1ubuntu0.26.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y ruby-rack-session
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Are YOU affected by USN-8190-2?

5-second check on your actual server. Reads /etc/os-release, uname -r, and dpkg-query; matches against the live USN + Debian Security Tracker feeds; tells you whether USN-8190-2 (and any other live CVE) applies. Anonymous, no signup.

curl https://mindsparkstack.com/scan.sh | bash

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