CVE-2026-31558 (GCVE-0-2026-31558)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:35 – Updated: 2026-08-05 12:23
VLAI
Title
LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
Summary
In the Linux kernel, the following vulnerability has been resolved: LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust kvm_get_vcpu_by_cpuid() takes a cpuid parameter whose type is int, so cpuid can be negative. Let kvm_get_vcpu_by_cpuid() return NULL for this case so as to make it more robust. This fix an out-of-bounds access to kvm_arch::phyid_map::phys_map[].
Severity
8.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 73516e9da512adc63ba3859fbd82a21f6257348f , < 596c3f8069c4792f22fce8c4452f44410032d910 (git)
Affected: 73516e9da512adc63ba3859fbd82a21f6257348f , < 878cf6acb4fd8ab4126cf9d369a5bb0e23123418 (git)
Affected: 73516e9da512adc63ba3859fbd82a21f6257348f , < 47857b05bd50db01e211a1b6f513d57901cd3e6b (git)
Affected: 73516e9da512adc63ba3859fbd82a21f6257348f , < 2db06c15d8c7a0ccb6108524e16cd9163753f354 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.10
Unaffected: 0 , < 6.10 (semver)
Unaffected: 6.12.80 , ≤ 6.12.* (semver)
Unaffected: 6.18.21 , ≤ 6.18.* (semver)
Unaffected: 6.19.11 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/loongarch/kvm/vcpu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "596c3f8069c4792f22fce8c4452f44410032d910",
              "status": "affected",
              "version": "73516e9da512adc63ba3859fbd82a21f6257348f",
              "versionType": "git"
            },
            {
              "lessThan": "878cf6acb4fd8ab4126cf9d369a5bb0e23123418",
              "status": "affected",
              "version": "73516e9da512adc63ba3859fbd82a21f6257348f",
              "versionType": "git"
            },
            {
              "lessThan": "47857b05bd50db01e211a1b6f513d57901cd3e6b",
              "status": "affected",
              "version": "73516e9da512adc63ba3859fbd82a21f6257348f",
              "versionType": "git"
            },
            {
              "lessThan": "2db06c15d8c7a0ccb6108524e16cd9163753f354",
              "status": "affected",
              "version": "73516e9da512adc63ba3859fbd82a21f6257348f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/loongarch/kvm/vcpu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.80",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.21",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.80",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.21",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.11",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust\n\nkvm_get_vcpu_by_cpuid() takes a cpuid parameter whose type is int, so\ncpuid can be negative. Let kvm_get_vcpu_by_cpuid() return NULL for this\ncase so as to make it more robust.\n\nThis fix an out-of-bounds access to kvm_arch::phyid_map::phys_map[]."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Exploitation requires local ability to run/control a LoongArch KVM guest or access KVM ioctls through `/dev/kvm`; the vulnerable code is not reachable directly over a network.\nAC:L - The attacker can directly supply the negative CPUID condition through guest hypercall register state or KVM interrupt-controller state, and no race or external timing condition is required.\nPR:L - The attacker needs access to a KVM VM or `/dev/kvm`, but the path does not require real host root or an init-namespace capability once KVM access is available.\nUI:N - No victim user action is required after the attacker can run the guest/KVM operation; the trigger is a direct hypercall or ioctl-driven interrupt-controller operation.\nS:C - The vulnerable component is host KVM, and a malicious guest or KVM user can affect host kernel memory, crossing the VM isolation boundary.\nC:H - The bug is an out-of-bounds access to the host kernel `phys_map` array, and under the required higher-severity rule this is treated as potentially exposing host kernel memory during exploitation.\nI:H - If the out-of-bounds entry is interpreted as an enabled vCPU, later interrupt-injection paths dereference and modify state through a bogus `struct kvm_vcpu` pointer, making host kernel memory corruption defensible.\nA:H - The reported failure includes UBSAN out-of-bounds warnings in host KVM, and attacker-controlled negative indices can reasonably cause host kernel oops, panic, or repeated denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:23:30.748Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/596c3f8069c4792f22fce8c4452f44410032d910"
        },
        {
          "url": "https://git.kernel.org/stable/c/878cf6acb4fd8ab4126cf9d369a5bb0e23123418"
        },
        {
          "url": "https://git.kernel.org/stable/c/47857b05bd50db01e211a1b6f513d57901cd3e6b"
        },
        {
          "url": "https://git.kernel.org/stable/c/2db06c15d8c7a0ccb6108524e16cd9163753f354"
        }
      ],
      "title": "LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31558",
    "datePublished": "2026-04-24T14:35:41.209Z",
    "dateReserved": "2026-03-09T15:48:24.116Z",
    "dateUpdated": "2026-08-05T12:23:30.748Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-31558",
      "date": "2026-09-27",
      "epss": "0.00175",
      "percentile": "0.06244"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "arch/loongarch/kvm/vcpu.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "596c3f8069c4792f22fce8c4452f44410032d910",
                    "status": "affected",
                    "version": "73516e9da512adc63ba3859fbd82a21f6257348f",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "878cf6acb4fd8ab4126cf9d369a5bb0e23123418",
                    "status": "affected",
                    "version": "73516e9da512adc63ba3859fbd82a21f6257348f",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "47857b05bd50db01e211a1b6f513d57901cd3e6b",
                    "status": "affected",
                    "version": "73516e9da512adc63ba3859fbd82a21f6257348f",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "2db06c15d8c7a0ccb6108524e16cd9163753f354",
                    "status": "affected",
                    "version": "73516e9da512adc63ba3859fbd82a21f6257348f",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "arch/loongarch/kvm/vcpu.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "6.10"
                  },
                  {
                    "lessThan": "6.10",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.12.*",
                    "status": "unaffected",
                    "version": "6.12.80",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.18.*",
                    "status": "unaffected",
                    "version": "6.18.21",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.19.*",
                    "status": "unaffected",
                    "version": "6.19.11",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.0",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "CD80DE3B-1F52-4735-A373-3F3F2440FA5D",
                    "versionEndExcluding": "6.12.80",
                    "versionStartIncluding": "6.10.1",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE",
                    "versionEndExcluding": "6.18.21",
                    "versionStartIncluding": "6.13",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7",
                    "versionEndExcluding": "6.19.11",
                    "versionStartIncluding": "6.19",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:6.10:-:*:*:*:*:*:*",
                    "matchCriteriaId": "9EA80796-744E-45F5-8632-2AB4F7889FCD",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
                    "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
                    "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
                    "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
                    "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*",
                    "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*",
                    "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*",
                    "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust\n\nkvm_get_vcpu_by_cpuid() takes a cpuid parameter whose type is int, so\ncpuid can be negative. Let kvm_get_vcpu_by_cpuid() return NULL for this\ncase so as to make it more robust.\n\nThis fix an out-of-bounds access to kvm_arch::phyid_map::phys_map[]."
          }
        ],
        "id": "CVE-2026-31558",
        "lastModified": "2026-06-17T10:33:58.553",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 8.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "CHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.0,
              "impactScore": 6.0,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-04-24T15:16:30.200",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/2db06c15d8c7a0ccb6108524e16cd9163753f354"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/47857b05bd50db01e211a1b6f513d57901cd3e6b"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/596c3f8069c4792f22fce8c4452f44410032d910"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/878cf6acb4fd8ab4126cf9d369a5bb0e23123418"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-125"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-28T11:52:37+00:00",
      "cve": "CVE-2026-31558",
      "id": "CVE-2026-31558",
      "initial_release_date": "2026-04-24T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31558.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-06T01:24:31Z",
      "cve": "CVE-2026-31558",
      "id": "CVE-2026-31558",
      "initial_release_date": "2026-04-25T01:39:29Z",
      "product_status:known_not_affected": "315",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-31558",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-31558.json",
      "version": "5"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.