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No exploitation reportedFix available

CVE-2023-6918

No exploitation reported by the sources we read.

  • Published2023-12-19
  • Fixed in0.10.6 · 0.9.8
  • WeaknessCWE-252

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 flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by different supported crypto backends. The return values from these were not properly checked, which could cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures, terminating the connection.

Timeline

dates in UTC
  1. 2023-12-1900:15CVE 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-2023-6918?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-6918?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
0.10≥ 0.10.0, < 0.10.60.10.6
0.9≥ 0.9.0, < 0.9.80.9.8
Fedoraproject fedora
BranchAffectedFixed in
38.x= 38no fix published
39.x= 39no fix published
Redhat enterprise linux
BranchAffectedFixed in
8.0= 8.0no fix published
9.0= 9.0no 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

  • libsshWolfiall versions · fixed in 0.10.6-r0
  • libsshUbuntu:Pro:18.04:LTSall versions · fixed in 0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3
  • libsshUbuntu:Pro:16.04:LTSall versions · fixed in 0.6.3-4.3ubuntu0.6+esm1
  • libsshUbuntu:22.04:LTSall versions · fixed in 0.9.6-2ubuntu0.22.04.3
  • libsshUbuntu:20.04:LTSall versions · fixed in 0.9.3-2ubuntu2.5
  • libsshTuxCare:CentOS:8.5all versions · fixed in 0.9.4-3.el8.tuxcare.els3and 2 other packages
  • libsshTuxCare:CentOS:8.4all versions · fixed in 0.9.4-3.el8.tuxcare.els3and 2 other packages
  • libsshTuxCare:AlmaLinux:9.2all versions · fixed in 0.10.4-8.el9.tuxcare.els1and 2 other packages

62 more package ranges on OSV.dev

Full record on NVD

Fix

  1. Update Libssh to 0.10.6 · 0.9.8

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

  • CNACVSS 3.13.7known since 2026-10-23
  • NVDCVSS 3.15.3read 2026-10-23
  • CNAweakness (CWE)CWE-252known since 2026-10-23
  • NVDweakness (CWE)CWE-252read 2026-10-23
  • FIRST EPSSEPSS score1.4 %2026-11-03
  • OSVaffected packages—
  • GitHub Advisoriesadvisory—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Published
2023-12-19
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-gpcj-wh2f-rr23

Frequently asked questions

What is CVE-2023-6918?

A flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by different supported crypto backends. The return values from these were not properly checked, which could cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures, terminating the connection.

Is CVE-2023-6918 actively exploited?

Active exploitation of CVE-2023-6918 has not been confirmed. Its EPSS score was 1.4% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-6918?

CVE-2023-6918 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

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