https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-09-30T16:09:32.870947+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/cve-2025-27220 CVE-2025-27220 2026-09-30T16:09:33.092372+00:00

Affected: ruby-lang CGI

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

 https://vulnerability.circl.lu/vuln/ghsa-mhwm-jh88-3gjf GHSA-mhwm-jh88-3gjf — CGI has Regular Expression Denial of Service (ReDoS) potential in Util#escapeElement 2026-09-30T16:09:33.092547+00:00

Affected: RubyGems: cgi

There is a possibility for Regular expression Denial of Service (ReDoS) by in the cgi gem. This vulnerability has been assigned the CVE identifier CVE-2025-27220. We recommend upgrading the cgi gem.

## Details

The regular expression used in `CGI::Util#escapeElement` is vulnerable to ReDoS. The crafted input could lead to a high CPU consumption.

This vulnerability only affects Ruby 3.1 and 3.2. If you are using these versions, please update CGI gem to version 0.3.5.1, 0.3.7, 0.4.2 or later.

## Affected versions

cgi gem versions <= 0.3.5, 0.3.6, 0.4.0 and 0.4.1.

## Credits

Thanks to svalkanov for discovering this issue. Also thanks to nobu for fixing this vulnerability.