CVE-2026-59849

EUVD-2026-46263
A flaw was found in libssh. Logic errors in automatic certificate-based public key authentication can cause libssh clients to loop indefinitely when configured certificates are missing or repeatedly rejected by a server, leading to denial of service.
Infinite Loop
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
3.1 LOW
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: 36.55%
Affected Products (NVD)
VendorProductVersion
libsshlibssh
0.11.0 ≤
𝑥
< 0.11.5
libsshlibssh
0.12.0
redhathardened_images
-
redhatenterprise_linux
10.0
redhatenterprise_linux
10.0
redhatenterprise_linux
10.2
redhatenterprise_linux_for_els
10.2
redhatenterprise_linux_for_eus
10.2
redhatenterprise_linux_for_ibm_z_systems
10.0
redhatenterprise_linux_for_ibm_z_systems
10.2
redhatenterprise_linux_for_ibm_z_systems_els
10.2
redhatenterprise_linux_for_ibm_z_systems_eus
10.2
redhatenterprise_linux_for_power_little_endian
10.0
redhatenterprise_linux_for_power_little_endian
10.2
redhatenterprise_linux_for_power_little_endian_els
10.2
redhatenterprise_linux_for_power_little_endian_eus
10.2
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
libssh
bookworm
vulnerable
bookworm (security)
vulnerable
forky
0.12.2-1
fixed
sid
0.12.2-1
fixed
trixie
0.11.5-0+deb13u1
fixed
trixie (security)
0.11.5-0+deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
libssh
bionic
not-affected
focal
not-affected
jammy
not-affected
noble
not-affected
resolute
Fixed 0.11.3-1ubuntu2.1
released
xenial
not-affected
Common Weakness Enumeration
References
https://access.redhat.com/errata/RHSA-2026:42922
https://access.redhat.com/errata/RHSA-2026:55855
https://access.redhat.com/security/cve/CVE-2026-59849
https://bugzilla.redhat.com/show_bug.cgi?id=2498182