CVE-2025-26466
CVE-2025-26466 · Openssh: denial-of-service in openssh
This page contains facts from public vulnerability sources. Check the original advisory before updating.
A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.
CVSS 5.9 · Medium · EPSS 40.6% · Fix available
- Published
- Updated
Affected products and versions
red hat enterprise linux 10
- Versions
- ≥ 0:9.9p1-7.el10_0: Not affected (rpm)
No fix published
red hat enterprise linux 9
- Versions
- ≥ 0:8.7p1-45.el9: Not affected (rpm)
No fix published
red hat enterprise linux 6
No fix published
red hat enterprise linux 7
No fix published
red hat enterprise linux 8
No fix published
red hat openshift container platform 4
No fix published
openssh Debian:13
- Affected ranges
- ECOSYSTEM: < 1:9.9p2-1
Update to 1:9.9p2-1
openssh Debian:14
- Affected ranges
- ECOSYSTEM: < 1:9.9p2-1
Update to 1:9.9p2-1
openssh Ubuntu:24.04:LTS
- Versions
- 1:9.3p1-1ubuntu3
- 1:9.4p1-1ubuntu1
- 1:9.6p1-3ubuntu1
- 1:9.6p1-3ubuntu2
- 1:9.6p1-3ubuntu11
- 1:9.6p1-3ubuntu12
- 1:9.6p1-3ubuntu13
- 1:9.6p1-3ubuntu13.3
- 1:9.6p1-3ubuntu13.4
- 1:9.6p1-3ubuntu13.5
- 1:9.6p1-3ubuntu13.7
- Affected ranges
- ECOSYSTEM: < 1:9.6p1-3ubuntu13.8
Update to 1:9.6p1-3ubuntu13.8
Original sources
- https://access.redhat.com/errata/RHBA-2025:6305
- https://access.redhat.com/errata/RHSA-2025:6993
- https://access.redhat.com/security/cve/CVE-2025-26466
- https://bugzilla.redhat.com/show_bug.cgi?id=2345043
- https://seclists.org/oss-sec/2025/q1/144
- https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt
- https://security.netapp.com/advisory/ntap-20250228-0002/
- https://www.openwall.com/lists/oss-security/2025/02/18/1
- https://www.openwall.com/lists/oss-security/2025/02/18/4
- https://bugzilla.suse.com/show_bug.cgi?id=1237041
- https://security-tracker.debian.org/tracker/CVE-2025-26466
- https://ubuntu.com/security/CVE-2025-26466
- http://seclists.org/fulldisclosure/2025/May/8
- http://seclists.org/fulldisclosure/2025/May/7
- http://seclists.org/fulldisclosure/2025/Feb/18
- https://www.vicarius.io/vsociety/posts/cve-2025-26466-detection-script-memory-consumption-vulnerability-in-openssh
- https://www.vicarius.io/vsociety/posts/cve-2025-26466-mitigation-script-memory-consumption-vulnerability-in-openssh
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
- https://nvd.nist.gov/vuln/detail/CVE-2025-26466