Local Denial of Service Vulnerability in libssh Affects Applications Using ProxyCommand
CVE-2026-59845

5.3MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 8
Red Hat Enterprise Linux 9
Red Hat Hardened Images
Vendor
CVE Published:
21 July 2026

What is CVE-2026-59845?

A vulnerability has been identified in libssh that affects systems utilizing the ProxyCommand feature. When a fork operation fails and is not properly handled, it can be recorded as an invalid process ID of -1. This improper management may allow signals to be inadvertently sent to processes within the caller's access, resulting in a potential denial of service. Systems using this library need to review their implementations of ProxyCommand to mitigate the impact of this flaw.

References

https://access.redhat.com/security/cve/CVE-2026-59845
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2498178
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Local
Attack Complexity:
High
Privileges Required:
Low
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank Halil Oktay (oblivionsage) for reporting this issue.
.