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Public proof of conceptFix available

CVE-2023-31606

A public proof of concept exists; no exploitation attested.

  • Published2023-06-06
  • Fixed in4.3.3
  • WeaknessCWE-1333

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 Regular Expression Denial of Service (ReDoS) issue was discovered in the sanitize_html function of redcloth gem v4.0.0. This vulnerability allows attackers to cause a Denial of Service (DoS) via supplying a crafted payload.

Timeline

dates in UTC
  1. 2023-06-0617:15CVE publishedNVD

Versions per branch

OSV · NVD
RedCloth
BranchAffectedFixed in
4.3< 4.3.34.3.3
Promptworks redcloth
BranchAffectedFixed in
4.x≥ 4.0.0, ≤ 4.3.2no fix published

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

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • ruby-redclothUbuntu:Pro:18.04:LTSall versions · fixed in 4.3.2-3ubuntu0.1~esm1
  • ruby-redclothUbuntu:Pro:16.04:LTSall versions · fixed in 4.2.9-5ubuntu0.1~esm1
  • ruby-redclothUbuntu:22.04:LTSall versions · fixed in 4.3.2-4ubuntu0.22.04.1
  • ruby-redclothUbuntu:20.04:LTSall versions · fixed in 4.3.2-3+deb10u1build0.20.04.1
  • ruby-redclothDebian:14all versions · fixed in 4.3.3-1
  • ruby-redclothDebian:13all versions · fixed in 4.3.3-1
  • ruby-redclothDebian:12all versions · no fixed version listed
  • ruby-redclothDebian:10all versions · fixed in 4.3.2-3+deb10u1

2 more package ranges on OSV.dev

Vendor advisories

  • CVE-2023-31606 Red Hat Product Security1 known affected

    RedCloth: Regular expression denial of service in sanitize_html function

    3scale-amp-system as a component of Red Hat 3scale API Management Platform 2

Full record on NVD

Fix

  1. Update RedCloth to 4.3.3
  2. No fix available, says the vendor Red Hat Product Security CVE-2023-31606 · 1 productAffected

Detection

read 2026-11-01 01:02 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2023-06-06
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-qcm3-vfq5-wfr2

Frequently asked questions

What is CVE-2023-31606?

A Regular Expression Denial of Service (ReDoS) issue was discovered in the sanitize_html function of redcloth gem v4.0.0. This vulnerability allows attackers to cause a Denial of Service (DoS) via supplying a crafted payload.

Is CVE-2023-31606 actively exploited?

Active exploitation of CVE-2023-31606 has not been confirmed. Its EPSS score was 1.5% on 2026-11-10, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-31606?

CVE-2023-31606 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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Sources for this record