{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "26844fee6adee9b1557d2279b0506285de9ee82b"
            },
            {
              "fixed": "78265cd066d73a5cb41c088fcae4a2515e480d97"
            },
            {
              "fixed": "ec3be7dc9391085a2d96700e159d66d1328b7ff6"
            },
            {
              "fixed": "2657439265d34a911886b916ba8be97ecc117d51"
            },
            {
              "fixed": "1e88b5f854bdb469424132e0bb44793ad7a7c20a"
            },
            {
              "fixed": "1c957773063ed3264953597e32990a748381caf6"
            },
            {
              "fixed": "ead63640d4e72e6f6d464f4e31f7fecb79af8869"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.1.0"
            },
            {
              "fixed": "6.1.167"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.130"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.77"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.17"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43265.json"
  },
  "details": "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",
  "modified": "2026-07-08T05:38:15.907654520Z",
  "published": "2026-05-06T11:28:51.552Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1c957773063ed3264953597e32990a748381caf6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1e88b5f854bdb469424132e0bb44793ad7a7c20a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2657439265d34a911886b916ba8be97ecc117d51"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/78265cd066d73a5cb41c088fcae4a2515e480d97"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ead63640d4e72e6f6d464f4e31f7fecb79af8869"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ec3be7dc9391085a2d96700e159d66d1328b7ff6"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43265.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43265"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "KVM: x86: Ignore -EBUSY when checking nested events from vcpu_block()"
}