Cross-site scripting in Rack - CVE-2026-25500
Published: February 19, 2026
Vulnerability identifier: #VU123073
CSH Severity: Low
CVSS v4 BT: 1.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]
CVE-ID: CVE-2026-25500
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data within Rack::Directory. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Affected software
Rack
Debian Linux
Ubuntu
ruby-rack (Ubuntu package)
ruby-rack (Debian package)
IBM Aspera Console
Debian Linux
Ubuntu
ruby-rack (Ubuntu package)
ruby-rack (Debian package)
IBM Aspera Console
How to mitigate CVE-2026-25500
Install updates from vendor's website.
Rack - addressed in versions 2.2.22, 3.1.20, 3.2.5
ruby-rack (Ubuntu package) - addressed in versions 2.0.7-2ubuntu0.1+esm9, 2.1.4-5ubuntu1.2+esm2, 2.2.7-1ubuntu0.6, 3.1.16-0.1ubuntu0.2
ruby-rack (Debian package) - addressed in versions 2.2.22-0+deb12u1, 3.1.20-0+deb13u1
IBM Aspera Console - update to 3.4.9
ruby-rack (Ubuntu package) - addressed in versions 2.0.7-2ubuntu0.1+esm9, 2.1.4-5ubuntu1.2+esm2, 2.2.7-1ubuntu0.6, 3.1.16-0.1ubuntu0.2
ruby-rack (Debian package) - addressed in versions 2.2.22-0+deb12u1, 3.1.20-0+deb13u1
IBM Aspera Console - update to 3.4.9