Resource exhaustion in Ruby-Lang Cgi

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. 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.

EPSS: 0.008 (55.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-27219?
CVE-2025-27219 is a medium-severity vulnerability in Ruby-Lang Cgi, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.8/10. Published 2025-03-04.
How severe is CVE-2025-27219?
Medium severity. CVSS v3 base score is 5.8 out of 10.
Is CVE-2025-27219 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.