No exploitation reportedFix available

CVE-2022-28738

Q: Is CVE-2022-28738 actively exploited?

Active exploitation of CVE-2022-28738 has not been confirmed. Its EPSS score was 3.0% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2022-28738?

CVE-2022-28738 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2022-05-09
Fixed in3.1.2 · 3.0.4
WeaknessCWE-415

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC

2022-05-0918:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2022-28738?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2022-28738?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Ruby

Branch	Affected	Fixed in	Source
3.1	≥ 3.1.0, < 3.1.2	3.1.2	NVD
3.0	≥ 3.0.0, < 3.0.4	3.0.4	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Ruby to 3.1.2 · 3.0.4

Advisories and patches

security-tracker.debian.orgPatch
www.ruby-lang.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-415read 2026-10-23
FIRST EPSSEPSS score3.0 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2022-05-09
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2022-28738?

Is CVE-2022-28738 actively exploited?

Active exploitation of CVE-2022-28738 has not been confirmed. Its EPSS score was 3.0% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2022-28738?

CVE-2022-28738 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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