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No exploitation reportedFix available

CVE-2023-40175

No exploitation reported by the sources we read.

  • Published2023-08-18
  • Fixed in6.3.1 · 5.6.7
  • WeaknessCWE-444

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

Puma is a Ruby/Rack web server built for parallelism. Prior to versions 6.3.1 and 5.6.7, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies and zero-length Content-Length headers in a way that allowed HTTP request smuggling. Severity of this issue is highly dependent on the nature of the web site using puma is. This could be caused by either incorrect parsing of trailing fields in chunked transfer encoding bodies or by parsing of blank/zero-length Content-Length headers. Both issues have been addressed and this vulnerability has been fixed in versions 6.3.1 and 5.6.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Timeline

dates in UTC
  1. 2023-08-1822:15CVE publishedNVD

Versions per branch

NVD · CISA-ADP · OSV
Puma
BranchAffectedFixed in
6.x≥ 6.0.0, < 6.3.16.3.1
5.6< 5.6.75.6.7

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

Products declared by the CNA1 product

As GitHub_M, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • puma
    Affected
    • = < 5.6.7no fix stated
    • = >= 6.0.0, < 6.3.1no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2023-08-18

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

  • candlepinRed Hat:satellite:6.14::el8all versions · fixed in 0:4.3.11-1.el8satand 1 other package
  • mosquittoRed Hat:satellite:6.14::el8all versions · fixed in 0:2.0.17-1.el8satand 2 other packages
  • mosquittoRed Hat:satellite_capsule:6.14::el8all versions · fixed in 0:2.0.17-1.el8satand 2 other packages
  • pumaUbuntu:Pro:22.04:LTSall versions · fixed in 5.5.2-2ubuntu2+esm1
  • pumaUbuntu:Pro:20.04:LTSall versions · fixed in 3.12.4-1ubuntu2+esm1
  • pumaUbuntu:24.04:LTSall versions · fixed in 5.6.5-4ubuntu2
  • pumaDebian:14all versions · fixed in 5.6.7-1
  • pumaDebian:13all versions · fixed in 5.6.7-1

24 more package ranges on OSV.dev

Vendor advisories

  • CVE-2023-40175 Red Hat Product Security4 products fixed · 6 known affected

    rubygem-puma: HTTP request smuggling when parsing chunked transfer encoding bodies and zero-length content-length headers

    3scale-amp-zync-container as a component of Red Hat 3scale API Management Platform 2 · tfm-rubygem-puma as a component of Red Hat Satellite 6 · tfm-rubygem-puma.src as a component of Red Hat Satellite 6 · +3 more

  • RHSA-2024:0797 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Satellite 6.14.2 Async Security Update

Full record on NVD

Fix

  1. Update Puma to 6.3.1 · 5.6.7
  2. Vendor fix Red Hat Product Security RHSA-2024:0797 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
  3. No fix available, says the vendor Red Hat Product Security CVE-2023-40175 · 3 productsAffected
  4. No fix planned, says the vendor Red Hat Product Security CVE-2023-40175 · 3 productsWill not fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • CISA-ADPSSVC decisionnone2024-10-07
  • CNACVSS 3.17.3known since 2026-10-23
  • NVDCVSS 3.19.8read 2026-10-23
  • CNAweakness (CWE)CWE-444known since 2026-10-23
  • FIRST EPSSEPSS score0.8 %2026-11-08
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryCRITICAL2023-08-18

Identifiers

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
2023-08-18
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-68xg-gqqm-vgj8

Frequently asked questions

What is CVE-2023-40175?

Puma is a Ruby/Rack web server built for parallelism. Prior to versions 6.3.1 and 5.6.7, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies and zero-length Content-Length headers in a way that allowed HTTP request smuggling. Severity of this issue is highly dependent on the nature of the web site using puma is. This could be caused by either incorrect parsing of trailing fields in chunked transfer encoding bodies or by parsing of blank/zero-length Content-Length headers. Both issues have been addressed and this vulnerability has been fixed in versions 6.3.1 and 5.6.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Is CVE-2023-40175 actively exploited?

Active exploitation of CVE-2023-40175 has not been confirmed. Its EPSS score was 0.8% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-40175?

CVE-2023-40175 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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