{"id":"CVE-2025-58151","aliases":["ALPINE-CVE-2025-58151","EUVD-2025-210447","GHSA-78gx-8v3c-jqwc"],"status":"published","title":"varstored: TOCTOU issues with mapped guest memory","description":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.","severity":{"version":"4.0","score":9.4,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00137,"percentile":0.03168,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-367"],"published":"2026-07-09T14:45:16Z","modified":"2026-09-29T19:10:00Z","products":[{"vendor":"xen","product":"varstored"}],"references":[{"url":"https://xenbits.xen.org/xsa/advisory-478.html"},{"url":"http://www.openwall.com/lists/oss-security/2026/01/27/2"},{"url":"http://xenbits.xen.org/xsa/advisory-478.html"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-58151"},{"url":"https://github.com/advisories/GHSA-78gx-8v3c-jqwc"},{"url":"https://security.alpinelinux.org/vuln/CVE-2025-58151","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2025-58151","title":"varstored: TOCTOU issues with mapped guest memory","description":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.","status":"published","published":"2026-07-09T14:45:16.531Z","modified":"2026-07-09T15:41:25.431Z","cvss":[{"version":"4.0","score":9.4,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"critical","assessor":"cna"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T14:32:37.027582Z"}],"euvd":[{"id":"EUVD-2025-210447","description":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.","status":"published","published":"2026-07-09T14:45:16Z","modified":"2026-07-09T15:41:25Z","cvss":[{"version":"4.0","score":9.4,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"critical"}],"updated_at":"2026-11-02T18:20:04.126011Z"}],"ghsa":[{"id":"GHSA-78gx-8v3c-jqwc","title":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a...","description":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.","status":"published","published":"2026-07-09T18:31:50Z","modified":"2026-07-09T18:31:59Z","cvss":[{"version":"4.0","score":9.4,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T15:09:22.189239Z"}],"nvd":[{"id":"CVE-2025-58151","description":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.","status":"published","published":"2026-07-09T16:16:33.817Z","modified":"2026-09-29T19:10:00.16Z","cvss":[{"version":"4.0","score":9.4,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","assessor":"secondary"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T14:12:02.535029Z"}],"osv":[{"id":"ALPINE-CVE-2025-58151","description":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.","status":"withdrawn","published":"2026-07-09T16:16:33.817Z","modified":"2026-07-14T08:03:34.397758576Z","cvss":[{"version":"4.0","score":9.4,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"}],"updated_at":"2026-11-02T15:27:50.269992Z"}]}}