CVE-2025-5372

HIGH
MEDIUM Priority: 0.04 BB Relevance: 68/100
Published: 2025-07-04 Modified: 2026-11-05 First seen: 2026-11-05 Status: active

Attack Surface

Network Low Complexity No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: Unchanged
C: High
I: High
A: High

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.

Weakness Classification (1)

References & Advisories (7)

https://access.redhat.com/errata/RHSA-2025:21977
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2025:23024
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:20610
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:24349
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:25911
vendor-advisory x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2369388
issue-tracking x_refsource_REDHAT

Bug Bounty Relevance

68 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

8.8 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploitation Probability

0.50%
Raw Score 0.005010
Percentile 43.1%
Date 2026-11-05

Intelligence Sources

mitre ref →
nvd ref →