USN-7960-1: Rack vulnerabilities

Publication date

14 January 2026

Overview

Several security issues were fixed in Rack.


Packages

  • ruby-rack - modular Ruby webserver interface

Details

It was discovered that Rack incorrectly handled certain query parameters.
An attacker could possibly use this issue to cause a limited denial of
service. This issue was only addressed in Ubuntu 20.04 LTS and
Ubuntu 22.04 LTS. (CVE-2025-59830)

It was discovered that Rack did not properly handle certain multipart
form data. An attacker could possibly use this issue to cause memory
exhaustion, leading to a denial of service. This issue was only addressed
in Ubuntu 22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 25.10.
(CVE-2025-61770, CVE-2025-61772)

It was discovered that Rack did not properly handle certain form fields.
An attacker could possibly use this issue to cause memory exhaustion,
leading to a denial of service. This issue was only addressed in Ubuntu
22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 25.10. (

It was discovered that Rack incorrectly handled certain query parameters.
An attacker could possibly use this issue to cause a limited denial of
service. This issue was only addressed in Ubuntu 20.04 LTS and
Ubuntu 22.04 LTS. (CVE-2025-59830)

It was discovered that Rack did not properly handle certain multipart
form data. An attacker could possibly use this issue to cause memory
exhaustion, leading to a denial of service. This issue was only addressed
in Ubuntu 22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 25.10.
(CVE-2025-61770, CVE-2025-61772)

It was discovered that Rack did not properly handle certain form fields.
An attacker could possibly use this issue to cause memory exhaustion,
leading to a denial of service. This issue was only addressed in Ubuntu
22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 25.10. (CVE-2025-61771)

It was discovered that Rack did not properly handle certain headers. An
attacker could possibly use this issue to bypass proxy access
restrictions and obtain sensitive information. (CVE-2025-61780)

Tomoya Yamashita discovered that Rack did not properly manage memory
under certain circumstances. An attacker could possibly use this issue to
cause memory exhaustion, leading to a denial of service. This issue was
only addressed in Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS
and Ubuntu 25.10. (CVE-2025-61919)


Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
25.10 questing ruby-rack –  3.1.16-0.1ubuntu0.1
24.04 LTS noble ruby-rack –  2.2.7-1ubuntu0.5
22.04 LTS jammy ruby-rack –  2.1.4-5ubuntu1.2
20.04 LTS focal ruby-rack –  2.0.7-2ubuntu0.1+esm8  
18.04 LTS bionic ruby-rack –  1.6.4-4ubuntu0.2+esm9  
16.04 LTS xenial ruby-rack –  1.6.4-3ubuntu0.2+esm9  

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