{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-0966","assignerOrgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","state":"PUBLISHED","assignerShortName":"redhat","dateReserved":"2026-01-14T21:54:59.132Z","datePublished":"2026-03-26T20:06:28.313Z","dateUpdated":"2026-05-11T16:13:21.843Z"},"containers":{"cna":{"title":"Libssh: libssh: denial of service via zero-length input in ssh_get_hexa()","metrics":[{"other":{"content":{"value":"Moderate","namespace":"https://access.redhat.com/security/updates/classification/"},"type":"Red Hat severity rating"}},{"cvssV3_0":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","version":"3.0"},"format":"CVSS"}],"descriptions":[{"lang":"en","value":"A flaw was found in libssh. The API function `ssh_get_hexa()` is vulnerable to a denial of service when processing zero-length input. This can be exploited remotely by an attacker during GSSAPI (Generic Security Service Application Program Interface) authentication if the server's logging verbosity is set to `SSH_LOG_PACKET (3)` or higher. Successful exploitation could lead to a self-Denial of Service of the per-connection daemon process."}],"affected":[{"vendor":"Red Hat","product":"Red Hat Hardened Images","collectionURL":"https://catalog.redhat.com/software/containers/","packageName":"libssh-main","defaultStatus":"affected","versions":[{"version":"0.12.0-1.1.hum1","lessThan":"*","versionType":"rpm","status":"unaffected"}],"cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libssh","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libssh2","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libssh2","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libssh","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libssh","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:9"]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libssh2","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"rhcos","defaultStatus":"affected","cpes":["cpe:/a:redhat:openshift:4"]}],"references":[{"url":"https://access.redhat.com/errata/RHSA-2026:7067","name":"RHSA-2026:7067","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-0966","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2433121","name":"RHBZ#2433121","tags":["issue-tracking","x_refsource_REDHAT"]},{"url":"https://www.libssh.org/2026/02/10/libssh-0-12-0-and-0-11-4-security-releases/"}],"datePublic":"2026-02-10T18:47:15.531Z","problemTypes":[{"descriptions":[{"cweId":"CWE-124","description":"Buffer Underwrite ('Buffer Underflow')","lang":"en","type":"CWE"}]}],"x_redhatCweChain":"CWE-124: Buffer Underwrite ('Buffer Underflow')","workarounds":[{"lang":"en","value":"To mitigate this issue, consider disabling GSSAPI authentication if it is not required, or reduce the `LogLevel` in the `sshd_config` file to a value lower than `SSH_LOG_PACKET` (e.g., `INFO`).\n\nTo disable GSSAPI authentication, add or modify the following line in `/etc/ssh/sshd_config`:\n`GSSAPIAuthentication no`\n\nTo reduce logging verbosity, add or modify the following line in `/etc/ssh/sshd_config`:\n`LogLevel INFO`\n\nAfter making changes to `sshd_config`, the `sshd` service must be restarted for the changes to take effect. This may temporarily interrupt active SSH sessions."}],"timeline":[{"lang":"en","time":"2026-01-26T23:14:46.617Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-02-10T18:47:15.531Z","value":"Made public."}],"credits":[{"lang":"en","value":"Red Hat would like to thank Jakub Jelen (libssh), Jun Xu, Kang Yang, and Yunhang Zhang for reporting this issue."}],"providerMetadata":{"orgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","shortName":"redhat","dateUpdated":"2026-05-11T16:13:21.843Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-27T19:52:22.819171Z","id":"CVE-2026-0966","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-27T20:01:45.907Z"}}]}}