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: 2025-03-04 Last update: 2025-11-03 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-27219 is rated Moderate Risk (43.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.35%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-27219

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-16 0.39% 0.35% -0.04%
2 2026-05-02 0.35% 0.39% +0.04%
3 2026-04-11 — 0.35% —

Full EPSS history (36 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-27219

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-27219

GitHub Security Advisory for CVE-2025-27219

GHSA-gh9q-2xrm-x6qv · Severity: medium · Ecosystem: rubygems — CGI has Denial of Service (DoS) potential in Cookie.parse

OS Trackers for CVE-2025-27219

vendor priority summary link
alpine medium CVE-2025-27219: 2 source package rows (ruby, ruby-net-imap); 6 state rows across 3 repos (3.19-main, 3.20-main, 3.21-main); fixed 6, open 0. https://security.alpinelinux.org/vuln/CVE-2025-27219
debian not yet assigned CVE-2025-27219 not yet assigned priority: Debian including 3 source packages (ruby2.7, ruby3.1, ruby3.3), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2025-27219
redhat medium — https://access.redhat.com/security/cve/CVE-2025-27219
suse medium CVE-2025-27219 severity moderate: SUSE including 310 source package names (2.23-77.6:libruby2_5-2_5-2.5.9-150000.4.41.1, 2.23-77.6:ruby2.5-2.5.9-150000.4.41.1, …), 942 product×package rows across 204 product lines (Container bci/ruby, Container suse/rmt-server, … (204 product lines)): Fixed 653, Known Affected 231, Known Not Affected 58. https://www.suse.com/security/cve/CVE-2025-27219/
ubuntu medium CVE-2025-27219 medium priority: Ubuntu including 7 source packages (jruby, ruby2.3, …), 54 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 31, needs-triage 13, released 8, ignored 2. https://ubuntu.com/security/CVE-2025-27219

Affected software / configurations for CVE-2025-27219

Vendor Product Version Raw CPE
ruby-lang cgi < 0.3.5.1 cpe:2.3:a:ruby-lang:cgi:*:*:*:*:*:ruby:*:*
ruby-lang cgi >= 0.4.0, < 0.4.2 cpe:2.3:a:ruby-lang:cgi:*:*:*:*:*:ruby:*:*
ruby-lang cgi 0.3.6 cpe:2.3:a:ruby-lang:cgi:0.3.6:*:*:*:*:ruby:*:*

References for CVE-2025-27219

cvelogic Threat Intelligence