{ "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": "2026-09-01T11:54:52.805Z" }, "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 Enterprise Linux 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "libssh", "defaultStatus": "affected", "versions": [ { "version": "0:0.12.0-2.el10", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/o:redhat:enterprise_linux:10.2" ] }, { "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "libssh", "defaultStatus": "affected", "versions": [ { "version": "0:0.10.4-18.el9", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/a:redhat:enterprise_linux:9::appstream", "cpe:/o:redhat:enterprise_linux:9::baseos" ] }, { "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "libssh", "defaultStatus": "affected", "versions": [ { "version": "0:0.10.4-18.el9", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/a:redhat:enterprise_linux:9::appstream", "cpe:/o:redhat:enterprise_linux:9::baseos" ] }, { "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 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 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": "openshift/ose-rhel-coreos-8", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:openshift:4" ] }, { "vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "openshift/ose-rhel-coreos-9", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:openshift:4" ] } ], "references": [ { "url": "https://access.redhat.com/errata/RHSA-2026:18160", "name": "RHSA-2026:18160", "tags": [ "vendor-advisory", "x_refsource_REDHAT" ] }, { "url": "https://access.redhat.com/errata/RHSA-2026:18683", "name": "RHSA-2026:18683", "tags": [ "vendor-advisory", "x_refsource_REDHAT" ] }, { "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": "2026-09-01T11:54:52.805Z" }, "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" } } ] } }