VulnerabilityModified

CVE-2025-27220

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

HIGH 7.5EPSS 0.74%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.74%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.74% probability · 53th percentile
CISA KEV: Not listed
Weakness: CWE-1333
Affected: ruby-lang/cgi
Source: cve@mitre.org

References

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

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.