{"id":"CVE-2025-26466","summary":"Openssh: denial-of-service in openssh","details":"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.","modified":"2026-08-12T03:51:37.313262168Z","published":"2025-02-28T21:25:28.861Z","related":["SUSE-SU-2025:0585-1","SUSE-SU-2025:20160-1","SUSE-SU-2025:20226-1","openSUSE-SU-2025:14820-1"],"database_specific":{"cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/26xxx/CVE-2025-26466.json","unresolved_ranges":[{"extracted_events":[{"introduced":"9.5p1"},{"last_affected":"9.9p1"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"redhat"},"references":[{"type":"WEB","url":"http://seclists.org/fulldisclosure/2025/Feb/18"},{"type":"WEB","url":"http://seclists.org/fulldisclosure/2025/May/7"},{"type":"WEB","url":"http://seclists.org/fulldisclosure/2025/May/8"},{"type":"WEB","url":"https://access.redhat.com/downloads/content/package-browser/"},{"type":"WEB","url":"https://seclists.org/oss-sec/2025/q1/144"},{"type":"WEB","url":"https://security-tracker.debian.org/tracker/CVE-2025-26466"},{"type":"WEB","url":"https://ubuntu.com/security/CVE-2025-26466"},{"type":"WEB","url":"https://www.openssh.com/"},{"type":"WEB","url":"https://www.openwall.com/lists/oss-security/2025/02/18/1"},{"type":"WEB","url":"https://www.openwall.com/lists/oss-security/2025/02/18/4"},{"type":"WEB","url":"https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt"},{"type":"WEB","url":"https://www.vicarius.io/vsociety/posts/cve-2025-26466-detection-script-memory-consumption-vulnerability-in-openssh"},{"type":"WEB","url":"https://www.vicarius.io/vsociety/posts/cve-2025-26466-mitigation-script-memory-consumption-vulnerability-in-openssh"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2025-26466"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/26xxx/CVE-2025-26466.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-26466"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20250228-0002/"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2345043"},{"type":"REPORT","url":"https://bugzilla.suse.com/show_bug.cgi?id=1237041"},{"type":"PACKAGE","url":"https://anongit.mindrot.org/openssh.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openssh/openssh-portable","events":[{"introduced":"80a2f64b8c1d27383cc83d182b73920d1e6a91f1"},{"last_affected":"53a80baaebda180f46e6e8571f3ff800e1f5c496"}],"database_specific":{"extracted_events":[{"introduced":"9.5-p1"},{"last_affected":"9.5-p1"},{"introduced":"9.6-NA"},{"last_affected":"9.6-NA"},{"introduced":"9.6-p1"},{"last_affected":"9.6-p1"},{"introduced":"9.7-NA"},{"last_affected":"9.7-NA"},{"introduced":"9.7-p1"},{"last_affected":"9.7-p1"},{"introduced":"9.8-NA"},{"last_affected":"9.8-NA"},{"introduced":"9.8-p1"},{"last_affected":"9.8-p1"},{"introduced":"9.9-p1"},{"last_affected":"9.9-p1"}],"source":"CPE_STRING","cpe":["cpe:2.3:a:openbsd:openssh:9.5:p1:*:*:*:*:*:*","cpe:2.3:a:openbsd:openssh:9.6:-:*:*:*:*:*:*","cpe:2.3:a:openbsd:openssh:9.6:p1:*:*:*:*:*:*","cpe:2.3:a:openbsd:openssh:9.7:-:*:*:*:*:*:*","cpe:2.3:a:openbsd:openssh:9.7:p1:*:*:*:*:*:*","cpe:2.3:a:openbsd:openssh:9.8:-:*:*:*:*:*:*","cpe:2.3:a:openbsd:openssh:9.8:p1:*:*:*:*:*:*","cpe:2.3:a:openbsd:openssh:9.9:p1:*:*:*:*:*:*"]}}],"versions":["9.5-p1","9.6-NA","9.7-NA","9.8-NA","9.9-p1","V_9_5_P1","V_9_9_P1","V_9_7_P1","V_9_6_P1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-26466.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}