CVE record · CVE-2026-59843

Libssh: libssh: denial of service via zero advertised channel packet size

CVSS 6.5 MediumEPSS 0.0057 · 47th percentile

Published by the CVE Program (CNA: redhat) at 21 Jul 2026, 11:16 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
Red Hat	Red Hat Enterprise Linux 10 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	unaffected 0:0.12.0-3.el10_2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	unaffected 0:0.9.6-17.el8_10 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	unaffected 0:0.9.6-17.el8_10 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 9 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	unaffected 0:0.10.4-19.el9_8 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 9 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	unaffected 0:0.10.4-19.el9_8 to before * rpm Other versions: affected
Red Hat	Red Hat Hardened Images Package name: libssh-main https://catalog.redhat.com/software/containers/	unaffected 0.12.1-4.hum1 to before * rpm Other versions: affected

Identifiers: CVE-2026-59843
CNA: redhat
Weakness (CWE): CWE-400 · CWE-835
Tags: Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 8
Red Hat Enterprise Linux 9
Red Hat Hardened Images
Denial of service
Published: 21 Jul 2026
Updated: 5 Nov 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
6.5	Medium	3.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H	CNA (redhat)

CISA KEV Not listed.
EPSS 0.0057, the 47th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

21 Jul 2026, 11:16 UTC Confirmed by the CVE List

Sources

References from the CNA

access.redhat.com/errata/RHSA-2026:42922 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:55855 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:62217 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:62218 vendor-advisoryredhat
access.redhat.com/security/cve/CVE-2026-59843 vdb-entryredhat
bugzilla.redhat.com/show_bug.cgi?id=2498176 issue-trackingredhat

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.