6.5
Medium
CVE-2026-59843 Libssh: libssh: denial of service via zero advertised channel packet size
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.
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitable remotely over the network, with an ordinary account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10 | Versions not published | |
| Red Hat Enterprise Linux 8 | Versions not published | |
| Red Hat Enterprise Linux 9 | Versions not published | |
| Red Hat Hardened Images 0.12 | earliest → < 0.12.1-4.hum1 | 0.12.1-4.hum1 |
References
- RHSA-2026:42922 access.redhat.com
- RHSA-2026:55855 access.redhat.com
- RHSA-2026:62217 access.redhat.com
- RHSA-2026:62218 access.redhat.com
- access.redhat.com access.redhat.com
- RHBZ#2498176 bugzilla.redhat.com
Timeline
- Published
- Last modified
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