Unrated severityOSV Advisory· Published Feb 28, 2025· Updated Feb 10, 2026
Openssh: denial-of-service in openssh
CVE-2025-26466
Description
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
9- osv-coords7 versionspkg:rpm/opensuse/openssh-askpass-gnome&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/openssh&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/openssh&distro=openSUSE%20Tumbleweedpkg:rpm/suse/openssh-askpass-gnome&distro=SUSE%20Linux%20Enterprise%20Module%20for%20Desktop%20Applications%2015%20SP6pkg:rpm/suse/openssh&distro=SUSE%20Linux%20Enterprise%20Module%20for%20Basesystem%2015%20SP6pkg:rpm/suse/openssh&distro=SUSE%20Linux%20Micro%206.0pkg:rpm/suse/openssh&distro=SUSE%20Linux%20Micro%206.1
< 9.6p1-150600.6.15.1+ 6 more
- (no CPE)range: < 9.6p1-150600.6.15.1
- (no CPE)range: < 9.6p1-150600.6.15.2
- (no CPE)range: < 9.9p2-1.1
- (no CPE)range: < 9.6p1-150600.6.15.1
- (no CPE)range: < 9.6p1-150600.6.15.2
- (no CPE)range: < 9.6p1-3.1
- (no CPE)range: < 9.6p1-slfo.1.1_2.1
Patches
Vulnerability mechanics
References
4- access.redhat.com/security/cve/CVE-2025-26466mitrevdb-entryx_refsource_REDHAT
- bugzilla.redhat.com/show_bug.cgimitreissue-trackingx_refsource_REDHAT
- seclists.org/oss-sec/2025/q1/144mitre
- www.qualys.com/2025/02/18/openssh-mitm-dos.txtmitre
News mentions
2- Pre-authentication Denial of Service attack in OpenSSH - CVE-2025-26466Fortinet PSIRT · Mar 11, 2025
- Risky Business #780 -- ASD torched Zservers data while admins were drunkRisky Business · Feb 19, 2025