Medium severity · published Jul 21, 2026
CVE-2026-59845
Libssh: libssh: denial of service via unchecked proxycommand fork() failure
5.9
CVSS
0.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 1% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Hardened Images · Red Hat
All versions, or not specified · source: vendor
EL
Enterprise Linux · Redhat
8.0; 9.0; 10.0 · source: NVD
HI
Hardened Images · Redhat
All versions, or not specified · source: NVD
LI
Libssh · Libssh
All versions, or not specified · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59845
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-59845
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:42922
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:55855
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:62217
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:62218
Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-59845
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2498178
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