Libssh: incorrect return code handling in ssh_kdf() in libssh (CVE-2025-5372) | HOL Guard CVE

Medium · CVSS 5.0CVE-2025-5372

Libssh: incorrect return code handling in ssh_kdf() in libssh

Answer in brief

CVE-2025-5372 records a Medium severity (CVSS 5.0) vulnerability in Libssh: incorrect return code handling in ssh_kdf() in libssh. The current sources do not mark it as known exploited. The current feed maps libssh/libssh (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 4, 2025Updated Sep 1, 2026Source checked Sep 21, 2026First seen by HOL Aug 6, 2026Material review Sep 1, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.0
Exploitation: Not marked as known exploited
Affected software: 8 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps libssh/libssh (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:a:libssh:libssh::::::::	Not reported	Not reported
cpe:2.3:a:redhat:openshift_container_platform:4.0:::::::*	Not reported	Not reported
cpe:2.3:o:redhat:enterprise_linux:10.0:::::::*	Not reported	Not reported
cpe:2.3:o:redhat:enterprise_linux:6.0:::::::*	Not reported	Not reported
cpe:2.3:o:redhat:enterprise_linux:7.0:::::::*	Not reported	Not reported
cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*	Not reported	Not reported
cpe:2.3:o:redhat:enterprise_linux:9.0:::::::*	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
libssh/libsshgeneric	>=0 <0.11.2	0.11.2

Recommended response

Check inventory. Check lockfiles and deployed manifests for libssh/libssh.
Review the reported fix. Update libssh/libssh to 0.11.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 4, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 6, 2026

Sources and claim methodology

Upstream source description

A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the ssh_kdf() function responsible for key derivation. Due to inconsistent interpretation of return values where OpenSSL uses 0 to indicate failure and libssh uses 0 for success—the function may mistakenly return a success status even when key derivation fails. This results in uninitialized cryptographic key buffers being used in subsequent communication, potentially compromising SSH sessions' confidentiality, integrity, and availability.

Quoted source text, attributed separately from HOL analysis.