Vulnerability-Lookup

FKIE_CVE-2026-31787

Vulnerability from fkie_nvd - Published: 2026-04-30 11:16 - Updated: 2026-05-06 19:38

Severity ?

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: fix double free via VMA splitting privcmd_vm_ops defines .close (privcmd_close), but neither .may_split nor .open. When userspace does a partial munmap() on a privcmd mapping, the kernel splits the VMA via __split_vma(). Since may_split is NULL, the split is allowed. vm_area_dup() copies vm_private_data (a pages array allocated in alloc_empty_pages()) into the new VMA without any fixup, because there is no .open callback. Both VMAs now point to the same pages array. When the unmapped portion is closed, privcmd_close() calls: - xen_unmap_domain_gfn_range() - xen_free_unpopulated_pages() - kvfree(pages) The surviving VMA still holds the dangling pointer. When it is later destroyed, the same sequence runs again, which leads to a double free. Fix this issue by adding a .may_split callback denying the VMA split. This is XSA-487 / CVE-2026-31787

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/1576ff3869cbd3620717195f971c85b7d7fd62b5	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/24daca4fc07f3ff8cd0e3f629cd982187f48436a	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2894a351fe2ea8684919d36df3188b9a35e3926f	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2b985d3a024b9e8c24e21671b34e855569763808	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/402d84ad9e89bd4cbfd07ca8598532b7021daf95	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/446ee446d9ae66f36e95c3c90bbcc4e56b94cde0	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/71bf829800758a6e3889096e4754ef47ba7fc850	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/dbf862ce9f009128ab86b234d91413a3e450beb4	Patch
af854a3a-2127-422b-91ae-364da2661108	http://www.openwall.com/lists/oss-security/2026/04/28/14	Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	http://xenbits.xen.org/xsa/advisory-487.html	Third Party Advisory

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	7.1
linux	linux_kernel	7.1

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "3DE3234F-8A05-4247-9F10-5D657450C37A",
              "versionEndExcluding": "5.10.254",
              "versionStartIncluding": "3.8",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "FA800016-0012-4E3F-A528-2A7F378A0A4A",
              "versionEndExcluding": "5.15.204",
              "versionStartIncluding": "5.11",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E6653854-B188-42DD-B8C5-0143F1956AB1",
              "versionEndExcluding": "6.1.170",
              "versionStartIncluding": "5.16",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "3CA3EF52-168A-4348-8F5F-356C9EB69261",
              "versionEndExcluding": "6.6.137",
              "versionStartIncluding": "6.2",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F17D292D-A9B5-4DC7-8002-51AB95335606",
              "versionEndExcluding": "6.12.85",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "85751F83-26BA-498C-90E7-E38A59C4564D",
              "versionEndExcluding": "6.18.26",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "C7C9A567-4F4F-4C61-BAD3-440B34C67118",
              "versionEndExcluding": "7.0.3",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxen/privcmd: fix double free via VMA splitting\n\nprivcmd_vm_ops defines .close (privcmd_close), but neither .may_split\nnor .open. When userspace does a partial munmap() on a privcmd mapping,\nthe kernel splits the VMA via __split_vma(). Since may_split is NULL,\nthe split is allowed. vm_area_dup() copies vm_private_data (a pages\narray allocated in alloc_empty_pages()) into the new VMA without any\nfixup, because there is no .open callback.\n\nBoth VMAs now point to the same pages array. When the unmapped portion\nis closed, privcmd_close() calls:\n    - xen_unmap_domain_gfn_range()\n    - xen_free_unpopulated_pages()\n    - kvfree(pages)\n\nThe surviving VMA still holds the dangling pointer. When it is later\ndestroyed, the same sequence runs again, which leads to a double free.\n\nFix this issue by adding a .may_split callback denying the VMA split.\n\nThis is XSA-487 / CVE-2026-31787"
    }
  ],
  "id": "CVE-2026-31787",
  "lastModified": "2026-05-06T19:38:53.743",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-04-30T11:16:21.087",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/1576ff3869cbd3620717195f971c85b7d7fd62b5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/24daca4fc07f3ff8cd0e3f629cd982187f48436a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/2894a351fe2ea8684919d36df3188b9a35e3926f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/2b985d3a024b9e8c24e21671b34e855569763808"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/402d84ad9e89bd4cbfd07ca8598532b7021daf95"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/446ee446d9ae66f36e95c3c90bbcc4e56b94cde0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/71bf829800758a6e3889096e4754ef47ba7fc850"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/dbf862ce9f009128ab86b234d91413a3e450beb4"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2026/04/28/14"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "http://xenbits.xen.org/xsa/advisory-487.html"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-415"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-31787 (GCVE-0-2026-31787)

Vulnerability from cvelistv5 – Published: 2026-04-30 10:31 – Updated: 2026-05-04 07:46

Title

xen/privcmd: fix double free via VMA splitting

Summary

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/dbf862ce9f009128a…
	https://git.kernel.org/stable/c/2b985d3a024b9e8c2…
	https://git.kernel.org/stable/c/1576ff3869cbd3620…
	https://git.kernel.org/stable/c/402d84ad9e89bd4cb…
	https://git.kernel.org/stable/c/2894a351fe2ea8684…
	https://git.kernel.org/stable/c/446ee446d9ae66f36…
	https://git.kernel.org/stable/c/71bf829800758a6e3…
	https://git.kernel.org/stable/c/24daca4fc07f3ff8c…

Impacted products

Vendor

Product

Version

Linux

Affected: d71f513985c22f1050295d1a7e4327cf9fb060da , < dbf862ce9f009128ab86b234d91413a3e450beb4 (git)
Affected: d71f513985c22f1050295d1a7e4327cf9fb060da , < 2b985d3a024b9e8c24e21671b34e855569763808 (git)
Affected: d71f513985c22f1050295d1a7e4327cf9fb060da , < 1576ff3869cbd3620717195f971c85b7d7fd62b5 (git)
Affected: d71f513985c22f1050295d1a7e4327cf9fb060da , < 402d84ad9e89bd4cbfd07ca8598532b7021daf95 (git)
Affected: d71f513985c22f1050295d1a7e4327cf9fb060da , < 2894a351fe2ea8684919d36df3188b9a35e3926f (git)
Affected: d71f513985c22f1050295d1a7e4327cf9fb060da , < 446ee446d9ae66f36e95c3c90bbcc4e56b94cde0 (git)
Affected: d71f513985c22f1050295d1a7e4327cf9fb060da , < 71bf829800758a6e3889096e4754ef47ba7fc850 (git)
Affected: d71f513985c22f1050295d1a7e4327cf9fb060da , < 24daca4fc07f3ff8cd0e3f629cd982187f48436a (git)

Linux

Affected: 3.8
Unaffected: 0 , < 3.8 (semver)
Unaffected: 5.10.254 , ≤ 5.10.* (semver)
Unaffected: 5.15.204 , ≤ 5.15.* (semver)
Unaffected: 6.1.170 , ≤ 6.1.* (semver)
Unaffected: 6.6.137 , ≤ 6.6.* (semver)
Unaffected: 6.12.85 , ≤ 6.12.* (semver)
Unaffected: 6.18.26 , ≤ 6.18.* (semver)
Unaffected: 7.0.3 , ≤ 7.0.* (semver)
Unaffected: 7.1-rc2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-04-30T10:39:37.622Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/04/28/14"
          },
          {
            "url": "http://xenbits.xen.org/xsa/advisory-487.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/xen/privcmd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "dbf862ce9f009128ab86b234d91413a3e450beb4",
              "status": "affected",
              "version": "d71f513985c22f1050295d1a7e4327cf9fb060da",
              "versionType": "git"
            },
            {
              "lessThan": "2b985d3a024b9e8c24e21671b34e855569763808",
              "status": "affected",
              "version": "d71f513985c22f1050295d1a7e4327cf9fb060da",
              "versionType": "git"
            },
            {
              "lessThan": "1576ff3869cbd3620717195f971c85b7d7fd62b5",
              "status": "affected",
              "version": "d71f513985c22f1050295d1a7e4327cf9fb060da",
              "versionType": "git"
            },
            {
              "lessThan": "402d84ad9e89bd4cbfd07ca8598532b7021daf95",
              "status": "affected",
              "version": "d71f513985c22f1050295d1a7e4327cf9fb060da",
              "versionType": "git"
            },
            {
              "lessThan": "2894a351fe2ea8684919d36df3188b9a35e3926f",
              "status": "affected",
              "version": "d71f513985c22f1050295d1a7e4327cf9fb060da",
              "versionType": "git"
            },
            {
              "lessThan": "446ee446d9ae66f36e95c3c90bbcc4e56b94cde0",
              "status": "affected",
              "version": "d71f513985c22f1050295d1a7e4327cf9fb060da",
              "versionType": "git"
            },
            {
              "lessThan": "71bf829800758a6e3889096e4754ef47ba7fc850",
              "status": "affected",
              "version": "d71f513985c22f1050295d1a7e4327cf9fb060da",
              "versionType": "git"
            },
            {
              "lessThan": "24daca4fc07f3ff8cd0e3f629cd982187f48436a",
              "status": "affected",
              "version": "d71f513985c22f1050295d1a7e4327cf9fb060da",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/xen/privcmd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.8"
            },
            {
              "lessThan": "3.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.254",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.204",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.170",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.137",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.85",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.26",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1-rc2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.254",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.204",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.170",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.137",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.85",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.26",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.3",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1-rc2",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxen/privcmd: fix double free via VMA splitting\n\nprivcmd_vm_ops defines .close (privcmd_close), but neither .may_split\nnor .open. When userspace does a partial munmap() on a privcmd mapping,\nthe kernel splits the VMA via __split_vma(). Since may_split is NULL,\nthe split is allowed. vm_area_dup() copies vm_private_data (a pages\narray allocated in alloc_empty_pages()) into the new VMA without any\nfixup, because there is no .open callback.\n\nBoth VMAs now point to the same pages array. When the unmapped portion\nis closed, privcmd_close() calls:\n    - xen_unmap_domain_gfn_range()\n    - xen_free_unpopulated_pages()\n    - kvfree(pages)\n\nThe surviving VMA still holds the dangling pointer. When it is later\ndestroyed, the same sequence runs again, which leads to a double free.\n\nFix this issue by adding a .may_split callback denying the VMA split.\n\nThis is XSA-487 / CVE-2026-31787"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-04T07:46:41.556Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/dbf862ce9f009128ab86b234d91413a3e450beb4"
        },
        {
          "url": "https://git.kernel.org/stable/c/2b985d3a024b9e8c24e21671b34e855569763808"
        },
        {
          "url": "https://git.kernel.org/stable/c/1576ff3869cbd3620717195f971c85b7d7fd62b5"
        },
        {
          "url": "https://git.kernel.org/stable/c/402d84ad9e89bd4cbfd07ca8598532b7021daf95"
        },
        {
          "url": "https://git.kernel.org/stable/c/2894a351fe2ea8684919d36df3188b9a35e3926f"
        },
        {
          "url": "https://git.kernel.org/stable/c/446ee446d9ae66f36e95c3c90bbcc4e56b94cde0"
        },
        {
          "url": "https://git.kernel.org/stable/c/71bf829800758a6e3889096e4754ef47ba7fc850"
        },
        {
          "url": "https://git.kernel.org/stable/c/24daca4fc07f3ff8cd0e3f629cd982187f48436a"
        }
      ],
      "title": "xen/privcmd: fix double free via VMA splitting",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31787",
    "datePublished": "2026-04-30T10:31:28.992Z",
    "dateReserved": "2026-03-09T15:48:24.141Z",
    "dateUpdated": "2026-05-04T07:46:41.556Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2026-31787

CVE-2026-31787 (GCVE-0-2026-31787)

Tags

Sightings

Nomenclature