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Vulnerability record · CVE-2025-27219 · published 4 March 2025

CVE-2025-27219: Ruby-lang cgi allocation without limits vulnerability

Ruby Lang · Cgi

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.

7.5 CVSS 3.1 High EPSS 0.85% · top 43.5% CWE-770 · Allocation without limits
7.5CVSS 3.1 base score
0.85%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References
17 Jun 2026Last modified by NVD

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/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2025-27219), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.