CVE-2023-22796

A regular expression based DoS vulnerability in Active Support <6.1.7.1 and <7.0.4.1. A specially crafted string passed to the underscore method can cause the regular expression engine to enter a state of catastrophic backtracking. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability.

Published: 2023-02-09 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-22796 is rated Moderate Risk (58.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.48%). 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-2023-22796

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 2026-04-21 1.73% 1.48% -0.25%
2 2026-03-13 1.33% 1.73% +0.40%
3 2026-03-05 — 1.33% —

Full EPSS history (38 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-22796

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
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-2023-22796

GitHub Security Advisory for CVE-2023-22796

GHSA-j6gc-792m-qgm2 · Severity: low · Ecosystem: rubygems — ReDoS based DoS vulnerability in Active Support's underscore

OS Trackers for CVE-2023-22796

vendor priority summary link
alpine — CVE-2023-22796: 1 source package rows (ruby-activesupport); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2023-22796
debian not yet assigned CVE-2023-22796 not yet assigned priority: Debian including 1 source packages (rails), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-22796
redhat medium — https://access.redhat.com/security/cve/CVE-2023-22796
suse high — https://www.suse.com/security/cve/CVE-2023-22796/
ubuntu medium CVE-2023-22796 medium priority: Ubuntu including 7 source packages (rails, rails-4.0, …), 55 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 30, needs-triage 13, ignored 12. https://ubuntu.com/security/CVE-2023-22796

Affected software / configurations for CVE-2023-22796

Vendor Product Version Raw CPE
activesupport_project activesupport < 6.1.7.1 cpe:2.3:a:activesupport_project:activesupport:*:*:*:*:*:ruby:*:*
activesupport_project activesupport >= 7.0.0, < 7.0.4.1 cpe:2.3:a:activesupport_project:activesupport:*:*:*:*:*:ruby:*:*

References for CVE-2023-22796

cvelogic Threat Intelligence