{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-43265", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:55.997Z", "datePublished": "2026-05-06T11:28:51.552Z", "dateUpdated": "2026-05-06T11:28:51.552Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-06T11:28:51.552Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Ignore -EBUSY when checking nested events from vcpu_block()\n\nIgnore -EBUSY when checking nested events after exiting a blocking state\nwhile L2 is active, as exiting to userspace will generate a spurious\nuserspace exit, usually with KVM_EXIT_UNKNOWN, and likely lead to the VM's\ndemise. Continuing with the wakeup isn't perfect either, as *something*\nhas gone sideways if a vCPU is awakened in L2 with an injected event (or\nworse, a nested run pending), but continuing on gives the VM a decent\nchance of surviving without any major side effects.\n\nAs explained in the Fixes commits, it _should_ be impossible for a vCPU to\nbe put into a blocking state with an already-injected event (exception,\nIRQ, or NMI). Unfortunately, userspace can stuff MP_STATE and/or injected\nevents, and thus put the vCPU into what should be an impossible state.\n\nDon't bother trying to preserve the WARN, e.g. with an anti-syzkaller\nKconfig, as WARNs can (hopefully) be added in paths where _KVM_ would be\nviolating x86 architecture, e.g. by WARNing if KVM attempts to inject an\nexception or interrupt while the vCPU isn't running."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/x86.c"], "versions": [{"version": "26844fee6adee9b1557d2279b0506285de9ee82b", "lessThan": "78265cd066d73a5cb41c088fcae4a2515e480d97", "status": "affected", "versionType": "git"}, {"version": "26844fee6adee9b1557d2279b0506285de9ee82b", "lessThan": "ec3be7dc9391085a2d96700e159d66d1328b7ff6", "status": "affected", "versionType": "git"}, {"version": "26844fee6adee9b1557d2279b0506285de9ee82b", "lessThan": "2657439265d34a911886b916ba8be97ecc117d51", "status": "affected", "versionType": "git"}, {"version": "26844fee6adee9b1557d2279b0506285de9ee82b", "lessThan": "1e88b5f854bdb469424132e0bb44793ad7a7c20a", "status": "affected", "versionType": "git"}, {"version": "26844fee6adee9b1557d2279b0506285de9ee82b", "lessThan": "1c957773063ed3264953597e32990a748381caf6", "status": "affected", "versionType": "git"}, {"version": "26844fee6adee9b1557d2279b0506285de9ee82b", "lessThan": "ead63640d4e72e6f6d464f4e31f7fecb79af8869", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/x86.c"], "versions": [{"version": "6.1", "status": "affected"}, {"version": "0", "lessThan": "6.1", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.77", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.17", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.6", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.1.167"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.6.130"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.12.77"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.18.17"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.19.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/78265cd066d73a5cb41c088fcae4a2515e480d97"}, {"url": "https://git.kernel.org/stable/c/ec3be7dc9391085a2d96700e159d66d1328b7ff6"}, {"url": "https://git.kernel.org/stable/c/2657439265d34a911886b916ba8be97ecc117d51"}, {"url": "https://git.kernel.org/stable/c/1e88b5f854bdb469424132e0bb44793ad7a7c20a"}, {"url": "https://git.kernel.org/stable/c/1c957773063ed3264953597e32990a748381caf6"}, {"url": "https://git.kernel.org/stable/c/ead63640d4e72e6f6d464f4e31f7fecb79af8869"}], "title": "KVM: x86: Ignore -EBUSY when checking nested events from vcpu_block()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Ignore -EBUSY when checking nested events from vcpu_block()\n\nIgnore -EBUSY when checking nested events after exiting a blocking state\nwhile L2 is active, as exiting to userspace will generate a spurious\nuserspace exit, usually with KVM_EXIT_UNKNOWN, and likely lead to the VM's\ndemise. Continuing with the wakeup isn't perfect either, as *something*\nhas gone sideways if a vCPU is awakened in L2 with an injected event (or\nworse, a nested run pending), but continuing on gives the VM a decent\nchance of surviving without any major side effects.\n\nAs explained in the Fixes commits, it _should_ be impossible for a vCPU to\nbe put into a blocking state with an already-injected event (exception,\nIRQ, or NMI). Unfortunately, userspace can stuff MP_STATE and/or injected\nevents, and thus put the vCPU into what should be an impossible state.\n\nDon't bother trying to preserve the WARN, e.g. with an anti-syzkaller\nKconfig, as WARNs can (hopefully) be added in paths where _KVM_ would be\nviolating x86 architecture, e.g. by WARNing if KVM attempts to inject an\nexception or interrupt while the vCPU isn't running."}], "id": "CVE-2026-43265", "lastModified": "2026-05-06T13:07:51.607", "metrics": {}, "published": "2026-05-06T12:16:47.510", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1c957773063ed3264953597e32990a748381caf6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1e88b5f854bdb469424132e0bb44793ad7a7c20a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2657439265d34a911886b916ba8be97ecc117d51"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/78265cd066d73a5cb41c088fcae4a2515e480d97"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ead63640d4e72e6f6d464f4e31f7fecb79af8869"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ec3be7dc9391085a2d96700e159d66d1328b7ff6"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{}

{}