VulnerabilityModified

CVE-2025-27219

In the CGI gem before 0.4.2 for Ruby, the CGI::Cookie.parse method in the CGI library contains a potential Denial of Service (DoS) vulnerability.

HIGH 7.5EPSS 0.83%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.83%). 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, the CGI::Cookie.parse method in the CGI library contains a potential Denial of Service (DoS) vulnerability. The method does not impose any limit on the length of the raw cookie value it processes. This oversight can lead to excessive resource consumption when parsing extremely large cookies.

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: 0.83% probability · 56th percentile
CISA KEV: Not listed
Weakness: CWE-770
Affected: ruby-lang/cgi
Source: cve@mitre.org

References

https://github.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2025-27219.ymlThird Party Advisory
https://hackerone.com/reports/2936778Permissions Required
https://lists.debian.org/debian-lts-announce/2025/03/msg00008.html

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