CVE-2026-59843

MediumCVSS 6.5/10Last modified Sep 1, 2026

Description

A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service.

Metrics

CVSS 3.1 6.5/10CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness enumeration

CWE-835 CWE-400

Affected software

Vendor	Product	Versions
Red Hat	Red Hat Enterprise Linux 10	—
Red Hat	Red Hat Enterprise Linux 8	—
Red Hat	Red Hat Enterprise Linux 8	—
Red Hat	Red Hat Enterprise Linux 9	—
Red Hat	Red Hat Enterprise Linux 9	—
Red Hat	Red Hat Hardened Images	—

References

https://access.redhat.com/errata/RHSA-2026:42922Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:55855
https://access.redhat.com/errata/RHSA-2026:62217
https://access.redhat.com/errata/RHSA-2026:62218
https://access.redhat.com/security/cve/CVE-2026-59843Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2498176Issue Tracking, Vendor Advisory

Timeline

Published: Jul 21, 2026
Last modified: Sep 1, 2026
NVD status: Modified

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