Resource exhaustion in Rack - CVE-2026-34827
Published: April 2, 2026
Vulnerability identifier: #VU124824
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-34827
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to application does not properly control consumption of internal resources within escape-heavy quoted parameters.. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.
Affected software
Rack
Ubuntu
ruby-rack (Ubuntu package)
Ubuntu
ruby-rack (Ubuntu package)
How to mitigate CVE-2026-34827
Install updates from vendor's website.
Rack - addressed in versions 3.1.21, 3.2.6
ruby-rack (Ubuntu package) - addressed in versions 1.5.2-3+deb8u3ubuntu1~esm11, 1.6.4-3ubuntu0.2+esm10, 1.6.4-4ubuntu0.2+esm10, 2.0.7-2ubuntu0.1+esm10, 2.1.4-5ubuntu1.2+esm3, 2.2.7-1ubuntu0.7, 3.1.16-0.1ubuntu0.3
ruby-rack (Ubuntu package) - addressed in versions 1.5.2-3+deb8u3ubuntu1~esm11, 1.6.4-3ubuntu0.2+esm10, 1.6.4-4ubuntu0.2+esm10, 2.0.7-2ubuntu0.1+esm10, 2.1.4-5ubuntu1.2+esm3, 2.2.7-1ubuntu0.7, 3.1.16-0.1ubuntu0.3