{"id":"CVE-2026-59845","state":"PUBLISHED","title":"Libssh: libssh: denial of service via unchecked proxycommand fork() failure","description":"A flaw was found in libssh. When ProxyCommand is used, an unchecked fork() failure can be stored as process ID -1; during cleanup, signals may then be sent across the caller's accessible process tree, leading to local denial of service.","publishedAt":"2026-07-21T11:26:43.884Z","updatedAt":"2026-09-01T20:01:47.686Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:N/A:H","source":"redhat"},"assigner":"redhat","products":["Red Hat Red Hat Enterprise Linux 10","Red Hat Red Hat Enterprise Linux 8","Red Hat Red Hat Enterprise Linux 9","Red Hat Red Hat Hardened Images"],"affected":[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.12.0-3.el10_2","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.9.6-17.el8_10","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:8::appstream","cpe:/o:redhat:enterprise_linux:8::baseos"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.9.6-17.el8_10","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:8::appstream","cpe:/o:redhat:enterprise_linux:8::baseos"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.10.4-19.el9_8","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream","cpe:/o:redhat:enterprise_linux:9::baseos"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.10.4-19.el9_8","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream","cpe:/o:redhat:enterprise_linux:9::baseos"]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","packageName":"libssh-main","defaultStatus":"affected","versions":[{"version":"0.12.1-4.hum1","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:hummingbird:1"]}],"references":["https://access.redhat.com/errata/RHSA-2026:42922","https://access.redhat.com/errata/RHSA-2026:55855","https://access.redhat.com/errata/RHSA-2026:62217","https://access.redhat.com/errata/RHSA-2026:62218","https://access.redhat.com/security/cve/CVE-2026-59845","https://bugzilla.redhat.com/show_bug.cgi?id=2498178"],"weaknesses":["CWE-390"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/59xxx/CVE-2026-59845.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-59845","state":"PUBLISHED","datePublished":"2026-07-21T11:26:43.884Z","dateUpdated":"2026-09-01T20:01:47.686Z","assignerShortName":"redhat","assignerOrgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","dateReserved":"2026-07-07T15:40:24.561Z"},"containers":{"cna":{"title":"Libssh: libssh: denial of service via unchecked proxycommand fork() failure","descriptions":[{"lang":"en","value":"A flaw was found in libssh. When ProxyCommand is used, an unchecked fork() failure can be stored as process ID -1; during cleanup, signals may then be sent across the caller's accessible process tree, leading to local denial of service."}],"affected":[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.12.0-3.el10_2","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.9.6-17.el8_10","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:8::appstream","cpe:/o:redhat:enterprise_linux:8::baseos"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.9.6-17.el8_10","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:8::appstream","cpe:/o:redhat:enterprise_linux:8::baseos"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.10.4-19.el9_8","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream","cpe:/o:redhat:enterprise_linux:9::baseos"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"libssh","defaultStatus":"affected","versions":[{"version":"0:0.10.4-19.el9_8","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream","cpe:/o:redhat:enterprise_linux:9::baseos"]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","packageName":"libssh-main","defaultStatus":"affected","versions":[{"version":"0.12.1-4.hum1","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:hummingbird:1"]}],"references":[{"url":"https://access.redhat.com/errata/RHSA-2026:42922","name":"RHSA-2026:42922","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/errata/RHSA-2026:55855","name":"RHSA-2026:55855","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/errata/RHSA-2026:62217","name":"RHSA-2026:62217","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/errata/RHSA-2026:62218","name":"RHSA-2026:62218","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-59845","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2498178","name":"RHBZ#2498178","tags":["issue-tracking","x_refsource_REDHAT"]}],"metrics":[{"other":{"content":{"value":"Moderate","namespace":"https://access.redhat.com/security/updates/classification/"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-390","description":"Detection of Error Condition Without Action","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"redhat","orgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","dateUpdated":"2026-09-01T20:01:47.686Z"},"datePublic":"2026-07-21T11:23:44.480Z","x_redhatCweChain":"CWE-390: Detection of Error Condition Without Action","workarounds":[{"lang":"en","value":"To mitigate this issue, avoid using the ProxyCommand feature in libssh client configurations. This prevents the vulnerable code path from being exercised, thereby eliminating the risk of local denial of service due to unchecked fork() failures."}],"timeline":[{"lang":"en","time":"2026-04-29T10:03:47.442Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-07-21T11:23:44.480Z","value":"Made public."}],"credits":[{"lang":"en","value":"Red Hat would like to thank Halil Oktay (oblivionsage) for reporting this issue."}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-23T14:29:59.822776Z","id":"CVE-2026-59845","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-390","type":"CWE","lang":"en","description":"CWE-390 Detection of Error Condition Without Action"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-23T14:30:03.721Z"}}]}}}