← Back to CVE Explorer

CVE-2026-52993

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: tipc: fix double-free in tipc_buf_append() tipc_msg_validate() can potentially reallocate the skb it is validating, freeing the old one. In tipc_buf_append(), it was being called with a pointer to a local variable which was a copy of the caller's skb pointer. If the skb was reallocated and validation subsequently failed, the error handling path would free the original skb pointer, which had already been freed, leading to double-free. Fix this by checking if head now points to a newly allocated reassembled skb. If it does, reassign *headbuf for later freeing operations.

Severity
CRITICAL
CVSS score
9.8 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-06-24 17:17:10.203000
Last modified
2026-10-19 20:18:53.853000
View original CVE JSON 
{
  "id": "CVE-2026-52993",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-06-24T17:17:10.203",
  "lastModified": "2026-10-19T20:18:53.853",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix double-free in tipc_buf_append()\n\ntipc_msg_validate() can potentially reallocate the skb it is validating,\nfreeing the old one.  In tipc_buf_append(), it was being called with a\npointer to a local variable which was a copy of the caller's skb\npointer.\n\nIf the skb was reallocated and validation subsequently failed, the error\nhandling path would free the original skb pointer, which had already\nbeen freed, leading to double-free.\n\nFix this by checking if head now points to a newly allocated reassembled\nskb.  If it does, reassign *headbuf for later freeing operations."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/tipc/msg.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "d618d09a68e4eed7a435beb2e355250f6f40664a",
              "lessThan": "a438975a6dcdbd70865978c021650d1485586f0b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d618d09a68e4eed7a435beb2e355250f6f40664a",
              "lessThan": "4ee4deadaae7cb2e3d53af0fc889cf92a73413c0",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d618d09a68e4eed7a435beb2e355250f6f40664a",
              "lessThan": "d3556656c6daebf8def751c7e71d11dd0a180d24",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d618d09a68e4eed7a435beb2e355250f6f40664a",
              "lessThan": "0274f24485fc38032d4093e463dc3ff5c7a667c9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d618d09a68e4eed7a435beb2e355250f6f40664a",
              "lessThan": "4d104882bc815d4ec666ace9155f5f52715879a6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d618d09a68e4eed7a435beb2e355250f6f40664a",
              "lessThan": "1d5e589055880fae229e229e1929e087dbe08cf3",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d618d09a68e4eed7a435beb2e355250f6f40664a",
              "lessThan": "29940fff14110ca48c5ccc168d121665b51bb778",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d618d09a68e4eed7a435beb2e355250f6f40664a",
              "lessThan": "d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/tipc/msg.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.15",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.15",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.258",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.209",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.175",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.141",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.91",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.33",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.0.10",
              "lessThanOrEqual": "7.0.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    },
    {
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "affectedData": [
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 10",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "kernel",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10.2"
          ],
          "versions": [
            {
              "version": "0:6.12.0-211.40.1.el10_2",
              "lessThan": "*",
              "versionType": "rpm",
              "status": "unaffected"
            }
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "kernel-rt",
          "cpes": [
            "cpe:/a:redhat:enterprise_linux:8::nfv"
          ],
          "versions": [
            {
              "version": "0:4.18.0-553.147.1.rt7.488.el8_10",
              "lessThan": "*",
              "versionType": "rpm",
              "status": "unaffected"
            }
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "kernel",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:8"
          ],
          "versions": [
            {
              "version": "0:4.18.0-553.147.1.el8_10",
              "lessThan": "*",
              "versionType": "rpm",
              "status": "unaffected"
            }
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 9",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "kernel",
          "cpes": [
            "cpe:/a:redhat:enterprise_linux:9",
            "cpe:/o:redhat:enterprise_linux:9"
          ],
          "versions": [
            {
              "version": "0:5.14.0-687.33.1.el9_8",
              "lessThan": "*",
              "versionType": "rpm",
              "status": "unaffected"
            }
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 6",
          "defaultStatus": "unaffected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "kernel",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:6"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 7",
          "defaultStatus": "unaffected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "kernel",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:7"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 7",
          "defaultStatus": "unaffected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "kernel-rt",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:7"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 9",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "kernel-rt",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:9"
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9
      },
      {
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T15:24:18.442775Z",
          "id": "CVE-2026-52993",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-415"
        }
      ]
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-763"
        }
      ]
    },
    {
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-763"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "4.15",
              "versionEndExcluding": "5.10.258",
              "matchCriteriaId": "38C5AF41-2A38-46B2-A60C-D2E3888BDBDA"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.11",
              "versionEndExcluding": "5.15.209",
              "matchCriteriaId": "919C10A9-7951-4A74-BADD-C135A0A8D8B4"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.16",
              "versionEndExcluding": "6.1.175",
              "matchCriteriaId": "92385813-D91D-480D-83A1-F423D2CBB2BA"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.2",
              "versionEndExcluding": "6.6.141",
              "matchCriteriaId": "97A9FFFA-22BB-4D5C-9790-5A2286E392F7"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.7",
              "versionEndExcluding": "6.12.91",
              "matchCriteriaId": "C918746B-DE6F-448F-A93E-A04C5481688D"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.13",
              "versionEndExcluding": "6.18.33",
              "matchCriteriaId": "96D99E49-380D-43AB-BDBA-25C3AD018A9C"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.19",
              "versionEndExcluding": "7.0.10",
              "matchCriteriaId": "A13475D2-59BF-4716-94B5-7C1D239A2CF4"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:45115",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:45116",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:47017",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:49212",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-52993",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2492437",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52993.json",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "tags": [
        "Third Party Advisory"
      ]
    }
  ]
}