CVE-2026-59843

medium

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.

References

https://bugzilla.redhat.com/show_bug.cgi?id=2498176

https://access.redhat.com/security/cve/CVE-2026-59843

https://access.redhat.com/errata/RHSA-2026:42922

Details

Source: Mitre, NVD

Published: 2026-07-21

Updated: 2026-07-22

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 6.5

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