What’s Vulnerable › Vulnerabilities

CVE-2025-27220

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-03-04 · updated 2026-06-17
• Weakness: CWE-1333

Description

In the CGI gem before 0.4.2 for Ruby, a Regular Expression Denial of Service (ReDoS) vulnerability exists in the Util#escapeElement method.

Affected products

• ruby-lang CGI: before 0.3.5.1; from 0.4.0 before 0.4.2; 0.3.6 — fixed in 0.3.5.1, 0.4.2

How to fix

Upgrade to a fixed version: ruby-lang CGI 0.3.5.1, 0.4.2. Check the vendor advisory for mitigations.

References

• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2025-27220.yml
• https://hackerone.com/reports/2890322
• https://lists.debian.org/debian-lts-announce/2025/03/msg00008.html

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