{"id":"CVE-2026-31786","revision":null,"records":[{"revision":"92a3f630569e408abbaf68482edb8ef1","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-31786","aliases":[],"title":"Buffer overflow in drivers/xen/sys-hypervisor.c","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBuffer overflow in drivers/xen/sys-hypervisor.c\n\nThe build id returned by HYPERVISOR_xen_version(XENVER_build_id) is\nneither NUL terminated nor a string.\n\nThe first causes a buffer overflow as sprintf in buildid_show will\nread and copy till it finds a NUL.\n\n00000000 f4 91 51 f4 dd 38 9e 9d 65 47 52 eb 10 71 db 50 |..Q..8..eGR..q.P|\n00000010 b9 a8 01 42 6f 2e 32 |...Bo.2|\n00000017\n\nSo use a memcpy instead of sprintf to have the correct value:\n\n00000000 f4 91 51 f4 dd 00 9e 9d 65 47 52 eb 10 71 db 50 |..Q.....eGR..q.P|\n00000010 b9 a8 01 42 |...B|\n00000014\n\n(the above have a hack to embed a zero inside and check it's\nreturned correctly).\n\nThis is XSA-485 / CVE-2026-31786","state":0,"publishedAt":"2026-04-30T10:31:28.293+00:00","modifiedAt":"2026-10-19T19:06:08.809+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"drivers/xen/sys-hypervisor.c\"\n ],\n \"versions\": [\n {\n \"version\": \"84b7625728ea311ea35bdaa0eded53c1c56baeaa\",\n \"lessThan\": \"e3af585e1728c917682b6a3de9a69b41fb9194d4\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"84b7625728ea311ea35bdaa0eded53c1c56baeaa\",\n \"lessThan\": \"8288d031a01dbacfde3fc643f7be3d23504de64d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"84b7625728ea311ea35bdaa0eded53c1c56baeaa\",\n \"lessThan\": \"f458ba102da97fafca106327086fc95f3fc764cb\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"84b7625728ea311ea35bdaa0eded53c1c56baeaa\",\n \"lessThan\": \"4b4defd2fce3f966c25adabf46644a85558f1169\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"84b7625728ea311ea35bdaa0eded53c1c56baeaa\",\n \"lessThan\": \"5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"84b7625728ea311ea35bdaa0eded53c1c56baeaa\",\n \"lessThan\": \"d5f59216650c51e5e3fcb7517c825bc8047f60ef\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"84b7625728ea311ea35bdaa0eded53c1c56baeaa\",\n \"lessThan\": \"52cecff98bda2c51eed1c6ce9d21c5d6268fb19d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"84b7625728ea311ea35bdaa0eded53c1c56baeaa\",\n \"lessThan\": \"27fdbab4221b375de54bf91919798d88520c6e28\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"drivers/xen/sys-hypervisor.c\"\n ],\n \"versions\": [\n {\n \"version\": \"4.13\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"4.13\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.254\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.204\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.170\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.137\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.85\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.26\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.0.3\",\n \"lessThanOrEqual\": \"7.0.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.1\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/e3af585e1728c917682b6a3de9a69b41fb9194d4","https://git.kernel.org/stable/c/8288d031a01dbacfde3fc643f7be3d23504de64d","https://git.kernel.org/stable/c/f458ba102da97fafca106327086fc95f3fc764cb","https://git.kernel.org/stable/c/4b4defd2fce3f966c25adabf46644a85558f1169","https://git.kernel.org/stable/c/5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a","https://git.kernel.org/stable/c/d5f59216650c51e5e3fcb7517c825bc8047f60ef","https://git.kernel.org/stable/c/52cecff98bda2c51eed1c6ce9d21c5d6268fb19d","https://git.kernel.org/stable/c/27fdbab4221b375de54bf91919798d88520c6e28"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31786","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-31786","identifiers":["CVE-2026-31786"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all 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