GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2025-37924 (GCVE-0-2025-37924)

Vulnerability from cvelistv5 – Published: 2025-05-20 15:21 – Updated: 2026-08-05 11:58
VLAI
Title
ksmbd: fix use-after-free in kerberos authentication
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in kerberos authentication Setting sess->user = NULL was introduced to fix the dangling pointer created by ksmbd_free_user. However, it is possible another thread could be operating on the session and make use of sess->user after it has been passed to ksmbd_free_user but before sess->user is set to NULL.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < e34a33d5d7e87399af0a138bb32f6a3e95dd83d2 (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < b447463562238428503cfba1c913261047772f90 (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < e18c616718018dfc440e4a2d2b94e28fe91b1861 (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 28c756738af44a404a91b77830d017bb0c525890 (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < e86e9134e1d1c90a960dd57f59ce574d27b9a124 (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.15
Unaffected: 0 , < 5.15 (semver)
Unaffected: 6.1.138 , ≤ 6.1.* (semver)
Unaffected: 6.6.90 , ≤ 6.6.* (semver)
Unaffected: 6.12.28 , ≤ 6.12.* (semver)
Unaffected: 6.14.6 , ≤ 6.14.* (semver)
Unaffected: 6.15 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T19:57:23.372Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/auth.c",
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e34a33d5d7e87399af0a138bb32f6a3e95dd83d2",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            },
            {
              "lessThan": "b447463562238428503cfba1c913261047772f90",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            },
            {
              "lessThan": "e18c616718018dfc440e4a2d2b94e28fe91b1861",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            },
            {
              "lessThan": "28c756738af44a404a91b77830d017bb0c525890",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            },
            {
              "lessThan": "e86e9134e1d1c90a960dd57f59ce574d27b9a124",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/auth.c",
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.138",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.90",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.28",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.14.*",
              "status": "unaffected",
              "version": "6.14.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.15",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.138",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.90",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.28",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.14.6",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.15",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in kerberos authentication\n\nSetting sess-\u003euser = NULL was introduced to fix the dangling pointer\ncreated by ksmbd_free_user. However, it is possible another thread could\nbe operating on the session and make use of sess-\u003euser after it has been\npassed to ksmbd_free_user but before sess-\u003euser is set to NULL."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "ksmbd kerberos authentication UAF. sess-\u003euser freed by one thread while another thread still accesses it during concurrent session setup. Attacker opens two connections to same session and sends concurrent SESSION_SETUP requests, controlling both sides of the race. Network-reachable, pre-authentication."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T11:58:25.065Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e34a33d5d7e87399af0a138bb32f6a3e95dd83d2"
        },
        {
          "url": "https://git.kernel.org/stable/c/b447463562238428503cfba1c913261047772f90"
        },
        {
          "url": "https://git.kernel.org/stable/c/e18c616718018dfc440e4a2d2b94e28fe91b1861"
        },
        {
          "url": "https://git.kernel.org/stable/c/28c756738af44a404a91b77830d017bb0c525890"
        },
        {
          "url": "https://git.kernel.org/stable/c/e86e9134e1d1c90a960dd57f59ce574d27b9a124"
        }
      ],
      "title": "ksmbd: fix use-after-free in kerberos authentication",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-37924",
    "datePublished": "2025-05-20T15:21:52.681Z",
    "dateReserved": "2025-04-16T04:51:23.969Z",
    "dateUpdated": "2026-08-05T11:58:25.065Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-37924",
      "date": "2026-09-18",
      "epss": "0.20744",
      "percentile": "0.97423"
    },
    "microsoft_vex": {
      "current_release_date": "2026-02-18T14:20:40.000Z",
      "cve": "CVE-2025-37924",
      "id": "msrc_CVE-2025-37924",
      "initial_release_date": "2025-05-02T00:00:00.000Z",
      "product_status:fixed": "2",
      "product_status:known_affected": "2",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "ksmbd: fix use-after-free in kerberos authentication",
      "url": "https://msrc.microsoft.com/csaf/vex/2025/msrc_cve-2025-37924.json",
      "version": "2"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "fs/smb/server/auth.c",
                  "fs/smb/server/smb2pdu.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "e34a33d5d7e87399af0a138bb32f6a3e95dd83d2",
                    "status": "affected",
                    "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "b447463562238428503cfba1c913261047772f90",
                    "status": "affected",
                    "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "e18c616718018dfc440e4a2d2b94e28fe91b1861",
                    "status": "affected",
                    "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "28c756738af44a404a91b77830d017bb0c525890",
                    "status": "affected",
                    "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "e86e9134e1d1c90a960dd57f59ce574d27b9a124",
                    "status": "affected",
                    "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "fs/smb/server/auth.c",
                  "fs/smb/server/smb2pdu.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "5.15"
                  },
                  {
                    "lessThan": "5.15",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.1.*",
                    "status": "unaffected",
                    "version": "6.1.138",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.6.*",
                    "status": "unaffected",
                    "version": "6.6.90",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.12.*",
                    "status": "unaffected",
                    "version": "6.12.28",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.14.*",
                    "status": "unaffected",
                    "version": "6.14.6",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "6.15",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "E8D2BFA7-4503-4FF2-A31E-B6BE242A7FEA",
                    "versionEndExcluding": "6.1.138",
                    "versionStartIncluding": "5.15",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "2BE1DB09-2D62-4C63-AF19-947300669741",
                    "versionEndExcluding": "6.6.90",
                    "versionStartIncluding": "6.2",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "5082CE19-0F3D-4521-AB3E-810D8255F500",
                    "versionEndExcluding": "6.12.28",
                    "versionStartIncluding": "6.7",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "19E5095E-5950-43EA-8E78-FC860855293F",
                    "versionEndExcluding": "6.14.6",
                    "versionStartIncluding": "6.13",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*",
                    "matchCriteriaId": "8D465631-2980-487A-8E65-40AE2B9F8ED1",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*",
                    "matchCriteriaId": "4C9D071F-B28E-46EC-AC61-22B913390211",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*",
                    "matchCriteriaId": "13FC0DDE-E513-465E-9E81-515702D49B74",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*",
                    "matchCriteriaId": "8C7B5B0E-4EEB-48F5-B4CF-0935A7633845",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in kerberos authentication\n\nSetting sess-\u003euser = NULL was introduced to fix the dangling pointer\ncreated by ksmbd_free_user. However, it is possible another thread could\nbe operating on the session and make use of sess-\u003euser after it has been\npassed to ksmbd_free_user but before sess-\u003euser is set to NULL."
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ksmbd: correcci\u00f3n del use-after-free en la autenticaci\u00f3n Kerberos. Se introdujo la configuraci\u00f3n sess-\u0026gt;user = NULL para corregir el puntero colgante creado por ksmbd_free_user. Sin embargo, es posible que otro hilo est\u00e9 operando en la sesi\u00f3n y utilice sess-\u0026gt;user despu\u00e9s de que se haya pasado a ksmbd_free_user, pero antes de que sess-\u0026gt;user se establezca en NULL."
          }
        ],
        "id": "CVE-2025-37924",
        "lastModified": "2026-06-17T09:15:42.463",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.8,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            },
            {
              "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": "2025-05-20T16:15:29.037",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/28c756738af44a404a91b77830d017bb0c525890"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/b447463562238428503cfba1c913261047772f90"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/e18c616718018dfc440e4a2d2b94e28fe91b1861"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/e34a33d5d7e87399af0a138bb32f6a3e95dd83d2"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/e86e9134e1d1c90a960dd57f59ce574d27b9a124"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-416"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-30T10:33:09+00:00",
      "cve": "CVE-2025-37924",
      "id": "CVE-2025-37924",
      "initial_release_date": "2025-05-20T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ksmbd: fix use-after-free in kerberos authentication",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-37924.json",
      "version": "3"
    }
  }
}



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.


Detection rules are retrieved from Rulezet.


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.