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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.008 (57.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 57.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: +0.000
Affected products
- Ruby-Lang Cgi — versions 0, 0.3.6, 0.4.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- hackerone.com/reports/2936778 (Permissions Required)
- github.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2025-27219.yml (Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108
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.