CVE & CISA-KEV Catalog

CVE-2026-59849

LOW
3.1
CVSS v3
NVD

Description

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.

How to fix

Remediation Available
libsshDebian
Fixed in:0.11.5-0+deb13u1CVE-2026-59849
Fixed in:0.12.1-1CVE-2026-59849
libsshRocky
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:main@aarch64RHSA-2026:42922
Fixed in:main@srcRHSA-2026:42922
Fixed in:main@noarchRHSA-2026:42922
libsshRed Hat / RHEL
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:main@aarch64RHSA-2026:42922
Fixed in:main@x86_64RHSA-2026:42922
Fixed in:main@srcRHSA-2026:42922
libssh-configRed Hat / RHEL
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
libssh-configRocky
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
libssh-debuginfoRed Hat / RHEL
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
libssh-debuginfoRocky
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
libssh-debugsourceRed Hat / RHEL
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
libssh-debugsourceRocky
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
libssh-develRocky
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
libssh-develRed Hat / RHEL
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855
Fixed in:0:0.12.0-3.el10_2RHSA-2026:55855

This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredLow
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityNone
IntegrityNone
AvailabilityLow

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

Exploit Intelligence

0.24%probability of exploitation in 30 days
16thpercentile

Low risk: more likely to be exploited than 16% of all known CVEs.

References

Issue Tracking1
Other references1

Related Vulnerabilities

Other CWE-835 vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2020-13935High7.587%-Fix
CVE-2020-36227High7.578%-Fix
CVE-2022-0778High7.573%-Fix
CVE-2024-20353High8.671%KEV-
CVE-2023-34966High7.562%-Fix
CVE-2019-14241High7.561%--

Common questions

How do I fix CVE-2026-59849?

Published advisories record a fix for 11 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-59849 being actively exploited?

Not that we know of. CVE-2026-59849 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.24% is the estimated probability that it will be exploited in the next 30 days. That is higher than 16% of all scored CVEs.

How severe is CVE-2026-59849?

CVE-2026-59849 has a CVSS v3 base score of 3.1, rated low. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-59849 affect?

Published advisories record a fix for libssh (Debian), libssh (Rocky), libssh (Red Hat / RHEL), libssh-config (Red Hat / RHEL), and 7 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-19.