GHSA-gh9q-2xrm-x6qv
CGI has Denial of Service (DoS) potential in Cookie.parse
Quick fix
GHSA-gh9q-2xrm-x6qv — cgi: upgrade to the fixed version with the command below.
bundle update cgiDetails
There is a possibility for DoS by in the cgi gem. This vulnerability has been assigned the CVE identifier CVE-2025-27219. We recommend upgrading the cgi gem.
## Details
CGI::Cookie.parse took super-linear time to parse a cookie string in some cases. Feeding a maliciously crafted cookie string into the method could lead to a Denial of Service.
Please update CGI gem to version 0.3.5.1, 0.3.7, 0.4.2 or later.
## Affected versions
cgi gem versions <= 0.3.5, 0.3.6, 0.4.0 and 0.4.1.
## Credits
Thanks to lio346 for discovering this issue. Also thanks to mame for fixing this vulnerability.
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-27219[ADVISORY]
- https://github.com/ruby/cgi/pull/52[WEB]
- https://github.com/ruby/cgi/pull/53[WEB]
- https://github.com/ruby/cgi/pull/54[WEB]
- https://hackerone.com/reports/2936778[WEB]
- https://github.com/ruby/cgi[PACKAGE]
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2025-27219.yml[WEB]
- https://lists.debian.org/debian-lts-announce/2025/03/msg00008.html[WEB]
- https://www.cve.org/CVERecord?id=CVE-2025-27219[WEB]