CVE-2025-27220

FAUCET Score

CVE-2025-27220 describes a Regular Expression Denial of Service (ReDoS) vulnerability in the Util#escapeElement method of the CGI gem for Ruby, affecting versions prior to 0.4.2, and by extension, Ruby itself. This high-severity vulnerability (CVSS 7.5) can be exploited remotely with low attack complexity, potentially leading to a denial of service (A:H) on affected systems. Currently, there is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		< 0.3.5.1CPE matchmatch criteria	cpe:2.3:a:ruby-lang:cgi::::::ruby::*
		>= 0.4.0, < 0.4.2CPE matchmatch criteria	cpe:2.3:a:ruby-lang:cgi::::::ruby::*
		0.3.6CPE matchmatch criteria	cpe:2.3:a:ruby-lang:cgi:0.3.6:::::ruby::
		>= 0, < 0.3.5.1CPE match	cpe:2.3:a:ruby-lang:cgi::::::ruby::*
		>= 0.3.6, < 0.3.7CPE match	cpe:2.3:a:ruby-lang:cgi::::::ruby::*

CVSS Data

CVSS version used by this source: 3.1

4.0MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

LOW

Exploitability Score

2.2

Impact Score

1.4

CvssVersion

3.1

Exploit Intelligence

EPSS Score

0.70%

Probability of exploitation in next 30 days

EPSS Percentile

49.5%

Percentile rank of EPSS score among Peer Group

As of 2026-07-27

Model: v2026.06.15

This CVE's current EPSS score of 0.0070 is in the 25th percentile among its peer group of 51,551 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (12)

microsoftpatch availablevia msrc

Product: 19723-17086Fixed in: 3.1.4-9

microsoftpatch availablevia msrc

Product: 19393-17084Fixed in: 3.3.5-3

microsoftpatch availablevia msrc

Product: azl3 ruby 3.3.5-3 on Azure Linux 3.0Fixed in: 3.3.5-3

microsoftpatch availablevia msrc

Product: cbl2 ruby 3.1.4-9 on CBL Mariner 2.0Fixed in: 3.1.4-9

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: ruby:3.1-8100020250407112943.489197e6

View patch

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 9Fixed in: ruby-0:3.0.7-165.el9_5

View patch

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 9Fixed in: ruby:3.1-9050020250404144903.9

View patch

rubygemspatch availablevia ghsa

Product: cgiFixed in: 0.3.5.1

rubygemspatch availablevia ghsa

Product: cgiFixed in: 0.3.7

rubygemspatch availablevia ghsa

Product: cgiFixed in: 0.4.2

redhatend of lifevia redhat_api

Product: Red Hat Enterprise Linux 9Fixed in: ruby:3.3/ruby

redhatend of lifevia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: ruby:2.5/ruby

Vendor Advisories (3)

microsoft2025-Mar/CVE-2025-27220Moderate

In the CGI gem before 0.4.2 for Ruby, a Regular Expression Denial of Service (ReDoS) vulnerability exists in the Util#escapeElement method.

Mar 11, 2025

rubygemsGHSA-mhwm-jh88-3gjfmedium

CGI has Regular Expression Denial of Service (ReDoS) potential in Util#escapeElement

Mar 3, 2025

redhatCVE-2025-27220Moderate

CGI: ReDoS in CGI::Util#escapeElement

Mar 3, 2025

References

lists.debian.org / debian-lts-announce/2025/03/msg00008.html

github.com / rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2025-27220.yml

Third Party Advisory

hackerone.com / reports/2890322

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