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No exploitation reportedFix available

CVE-2023-1667

No exploitation reported by the sources we read.

  • Published2023-05-26
  • WeaknessCWE-476

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 NULL pointer dereference was found In libssh during re-keying with algorithm guessing. This issue may allow an authenticated client to cause a denial of service.

Timeline

dates in UTC
  1. 2023-05-2618:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-03 15:37 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-2023-1667?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-1667?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Libssh
BranchAffectedFixed in
0.9≥ 0.9.1, ≤ 0.9.6no fix published
0.10≥ 0.10.0, ≤ 0.10.4no fix published
Redhat enterprise linux
BranchAffectedFixed in
8.0= 8.0no fix published
9.0= 9.0no fix published
Debian debian linux
BranchAffectedFixed in
10.0= 10.0no fix published

1 more product in the sources.

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

  • libsshUbuntu:Pro:18.04:LTSall versions · no fixed version listed
  • libsshUbuntu:Pro:16.04:LTSall versions · no fixed version listed
  • libsshUbuntu:22.04:LTSall versions · fixed in 0.9.6-2ubuntu0.22.04.1
  • libsshUbuntu:20.04:LTSall versions · fixed in 0.9.3-2ubuntu2.3
  • libsshTuxCare:CentOS:8.5all versions · fixed in 0.9.4-3.el8.tuxcare.els2and 2 other packages
  • libsshTuxCare:CentOS:8.4all versions · fixed in 0.9.4-3.el8.tuxcare.els2and 2 other packages
  • libsshTuxCare:AlmaLinux:9.2all versions · fixed in 0.10.4-8.el9.tuxcare.els2and 2 other packages
  • libsshSUSE:Manager Server 4.3all versions · fixed in 0.9.8-150400.3.3.1

45 more package ranges on OSV.dev

Vendor advisories

  • RHSA-2024:0538 Red Hat Product Security32 products fixed

    Red Hat Security Advisory: libssh security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2024:0538 · 32 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing these updated packages, all running applications using libssh must be restarted for this update to take effect.

Advisories and patches

Detection

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

Sources

  • NVDCVSS 3.16.5read 2026-10-23
  • CNAweakness (CWE)CWE-476known since 2026-10-23
  • NVDweakness (CWE)CWE-476read 2026-10-23
  • FIRST EPSSEPSS score1.3 %2026-11-03
  • OSVaffected packages—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Published
2023-05-26
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2023-1667?

A NULL pointer dereference was found In libssh during re-keying with algorithm guessing. This issue may allow an authenticated client to cause a denial of service.

Is CVE-2023-1667 actively exploited?

Active exploitation of CVE-2023-1667 has not been confirmed. Its EPSS score was 1.3% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-1667?

CVE-2023-1667 has a CVSS v3 base score of 6.5 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

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