CVE-2026-59845

Libssh: libssh: denial of service via unchecked proxycommand fork() failure

MEDIUM
5.9
CVSS Score
Published: July 21, 2026 at 11:26 AM UTC
Updated: September 1, 2026 at 09:18 PM UTC
3 products affected across 2 vendorsEnterprise LinuxHardened ImagesLibssh

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

A flaw was found in libssh. When ProxyCommand is used, an unchecked fork() failure can be stored as process ID -1; during cleanup, signals may then be sent across the caller's accessible process tree, leading to local denial of service.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
Vendor states this is fixed in 0:0.10.4-19.el9_8 (unaffected)
Vendor states this is fixed in 0:0.12.0-3.el10_2 (unaffected)
Vendor states this is fixed in 0:0.9.6-17.el8_10 (unaffected)
Vendor states this is fixed in 0.12.1-4.hum1 (unaffected)

References (6)

VDB Entryx_refsource_REDHATVendor Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-59845
Issue Trackingx_refsource_REDHATVendor Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2498178
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:42922
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:55855
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:62217

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-390

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