Red HatCVE-2026-59843
Red Hat libssh: denial of service
Medium6.5CVE-2026-59843 · Published Jul 21, 2026 · updated Sep 1, 2026
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.
Affected versions
The source does not list versions here. See the source advisory for affected products and fixes.
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-835, CWE-400
- www.cve.org/CVERecord?id=CVE-2026-59843
- nvd.nist.gov/vuln/detail/CVE-2026-59843
- access.redhat.com/errata/RHSA-2026:42922
- access.redhat.com/errata/RHSA-2026:55855
- access.redhat.com/errata/RHSA-2026:62217
- access.redhat.com/errata/RHSA-2026:62218
- access.redhat.com/security/cve/CVE-2026-59843
- bugzilla.redhat.com/show_bug.cgi?id=2498176
More Red Hat advisories
All Red Hat| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Jul 21 | Red Hat libarchive: integer overflow | Low2.9 | No fix yet |
| Jul 21 | Red Hat Enterprise Linux 10: information disclosure | Low3.4 | No fix yet |
| Jul 21 | Red Hat Enterprise Linux 10: out-of-bounds read | Medium4.2 | No fix yet |
| Jul 21 | Red Hat ansible-core: argument injection | High7.8 | No fix yet |
| Jul 21 | Red Hat libssh. Logic errors: denial of service | Low3.1 | No fix yet |
| Jul 21 | Red Hat libssh: use after free | Medium4.3 | No fix yet |