{"id":"CVE-2026-23557","state":"PUBLISHED","title":"Xenstored DoS via XS_RESET_WATCHES command","description":"Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES\ncommand within a transaction due to an assert() triggering.\n\nIn case xenstored was built with NDEBUG #defined nothing bad will\nhappen, as assert() is doing nothing in this case. Note that the\ndefault is not to define NDEBUG for xenstored builds even in release\nbuilds of Xen.","publishedAt":"2026-05-19T12:49:42.202Z","updatedAt":"2026-05-19T14:42:45.464Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H","source":"CISA-ADP"},"assigner":"XEN","products":["Xen Xen"],"affected":[{"vendor":"Xen","product":"Xen","defaultStatus":"unknown","versions":[{"version":"consult Xen advisory XSA-484","status":"unknown"}]}],"references":["https://xenbits.xenproject.org/xsa/advisory-484.html","http://www.openwall.com/lists/oss-security/2026/04/28/11","http://xenbits.xen.org/xsa/advisory-484.html"],"weaknesses":["CWE-617"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23557.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23557","state":"PUBLISHED","datePublished":"2026-05-19T12:49:42.202Z","dateUpdated":"2026-05-19T14:42:45.464Z","assignerShortName":"XEN","assignerOrgId":"23aa2041-22e1-471f-9209-9b7396fa234f","dateReserved":"2026-01-14T13:07:36.961Z"},"containers":{"cna":{"title":"Xenstored DoS via XS_RESET_WATCHES command","descriptions":[{"lang":"en","value":"Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES\ncommand within a transaction due to an assert() triggering.\n\nIn case xenstored was built with NDEBUG #defined nothing bad will\nhappen, as assert() is doing nothing in this case. Note that the\ndefault is not to define NDEBUG for xenstored builds even in release\nbuilds of Xen."}],"affected":[{"vendor":"Xen","product":"Xen","defaultStatus":"unknown","versions":[{"version":"consult Xen advisory XSA-484","status":"unknown"}]}],"references":[{"url":"https://xenbits.xenproject.org/xsa/advisory-484.html"}],"providerMetadata":{"shortName":"XEN","orgId":"23aa2041-22e1-471f-9209-9b7396fa234f","dateUpdated":"2026-05-19T12:49:42.202Z"},"datePublic":"2026-04-28T12:00:00.000Z","impacts":[{"descriptions":[{"lang":"en","value":"Any unprivileged domain can cause xenstored to crash, causing a\nDoS (denial of service) for any Xenstore action. This will result\nin an inability to perform further domain administration on the host."}]}],"configurations":[{"lang":"en","value":"All Xen systems from Xen 4.2 onwards are vulnerable. Systems up to\nXen 4.1 are not vulnerable.\n\nSystems using the C variant of xenstored or xenstore-stubdom built\nwithout NDEBUG are vulnerable. Systems using the OCaml variant of\nXenstore (oxenstored), or the C variant (xenstored or xenstore-stubdom)\nbuilt with NDEBUG defined are not vulnerable."}],"workarounds":[{"lang":"en","value":"There is no known mitigation available."}],"credits":[{"lang":"en","type":"finder","value":"This issue was discovered by Andrii Sultanov of Vates."}]},"adp":[{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/04/28/11"},{"url":"http://xenbits.xen.org/xsa/advisory-484.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-05-19T13:06:41.611Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"CHANGED","version":"3.1","baseScore":6.5,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-05-19T14:42:12.994792Z","id":"CVE-2026-23557","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-617","type":"CWE","lang":"en","description":"CWE-617 Reachable Assertion"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-19T14:42:45.464Z"}}]}}}