CVE-2022-28738

A double free was found in the Regexp compiler in Ruby 3.x before 3.0.4 and 3.1.x before 3.1.2. If a victim attempts to create a Regexp from untrusted user input, an attacker may be able to write to unexpected memory locations.

Published: 2022-05-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-28738 is rated High Risk (70.4/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.57%). EPSS rose +2.10% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize 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-2022-28738

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 2026-06-15 0.47% 2.57% +2.10%
2 2026-05-22 0.37% 0.47% +0.10%
3 2026-03-04 — 0.37% —

Full EPSS history (44 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-28738

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2022-28738

OS Trackers for CVE-2022-28738

vendor priority summary link
alpine — CVE-2022-28738: 1 source package rows (ruby); 12 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 5. https://security.alpinelinux.org/vuln/CVE-2022-28738
debian unimportant CVE-2022-28738 unimportant priority: Debian including 1 source packages (ruby2.7), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2022-28738
gentoo normal CVE-2022-28738: 1 GLSA(s) (202401-27), 1 atom(s) (dev-lang/ruby); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-28738
redhat medium — https://access.redhat.com/security/cve/CVE-2022-28738
ubuntu medium CVE-2022-28738 medium priority: Ubuntu including 4 source packages (ruby2.3, ruby2.5, ruby2.7, ruby3.0), 11 status rows across 7 suites (bionic, focal, impish, jammy, kinetic, upstream, xenial): not-affected 8, released 2, DNE 1. https://ubuntu.com/security/CVE-2022-28738

Affected software / configurations for CVE-2022-28738

Vendor Product Version Raw CPE
ruby-lang ruby >= 3.0.0, < 3.0.4 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby >= 3.1.0, < 3.1.2 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*

References for CVE-2022-28738

cvelogic Threat Intelligence