UBUNTU-CVE-2026-39324

See a problem?
Please try reporting it to the source first.

Source

https://ubuntu.com/security/CVE-2026-39324

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39324.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-39324

Upstream

CVE-2026-39324

Downstream

USN-8190-1

USN-8190-2

Related

Published

2026-04-07T18:16:00Z

Modified

2026-05-20T16:25:38.418643208Z

Severity

9.3 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

Rack::Session is a session management implementation for Rack. From 2.0.0 to before 2.1.2, Rack::Session::Cookie incorrectly handles decryption failures when configured with secrets:. If cookie decryption fails, the implementation falls back to a default decoder instead of rejecting the cookie. This allows an unauthenticated attacker to supply a crafted session cookie that is accepted as valid session data without knowledge of any configured secret. Because this mechanism is used to load session state, an attacker can manipulate session contents and potentially gain unauthorized access. This vulnerability is fixed in 2.1.2.

References

Affected packages

Ubuntu:25.10 / ruby-rack-session

Package

Name: ruby-rack-session
Purl: pkg:deb/ubuntu/ruby-rack-session?arch=source&distro=questing

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

2.1.1-0.1ubuntu0.1

Affected versions

2.*

2.1.1-0.1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "2.1.1-0.1ubuntu0.1",
            "binary_name": "ruby-rack-session"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39324.json"

Ubuntu:26.04:LTS / ruby-rack-session