{"id":"CVE-2025-26466","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-26466","generatedAt":"2026-11-03T22:42:50.484Z","title":"A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side.","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.","published":"2025-02-28T22:15:40.000Z","lastModified":"2026-10-21T17:17:29.000Z","status":"Modified","sourceIdentifier":"secalert@redhat.com","cvss":{"version":"3.1","score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-770"],"affected":["openbsd/openssh","canonical/ubuntu linux","debian/debian linux"],"epss":{"score":0.38682,"percentile":0.9858,"date":"2026-11-02","history":[{"date":"2026-10-25","score":0.38682,"percentile":0.98569}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 38.7%, higher than 99% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"https://access.redhat.com/errata/RHBA-2025:6305","source":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:6993","source":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2025-26466","tags":["Third Party Advisory"],"source":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2345043","tags":["Issue Tracking"],"source":"secalert@redhat.com"},{"url":"https://seclists.org/oss-sec/2025/q1/144","source":"secalert@redhat.com"},{"url":"https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt","tags":["Third Party Advisory"],"source":"secalert@redhat.com"},{"url":"http://seclists.org/fulldisclosure/2025/Feb/18","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://seclists.org/fulldisclosure/2025/May/7","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://seclists.org/fulldisclosure/2025/May/8","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.suse.com/show_bug.cgi?id=1237041","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security-tracker.debian.org/tracker/CVE-2025-26466","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20250228-0002/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://ubuntu.com/security/CVE-2025-26466","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.openwall.com/lists/oss-security/2025/02/18/1","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.openwall.com/lists/oss-security/2025/02/18/4","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.vicarius.io/vsociety/posts/cve-2025-26466-detection-script-memory-consumption-vulnerability-in-openssh","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.vicarius.io/vsociety/posts/cve-2025-26466-mitigation-script-memory-consumption-vulnerability-in-openssh","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","source":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt","tags":["Third Party Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-26466","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}