« Volver al listado

CVE-2026-31719

Estado: AnalizadaAlta (7.5)—

In the Linux kernel, the following vulnerability has been resolved:

crypto: krb5enc - fix async decrypt skipping hash verification

krb5enc_dispatch_decrypt() sets req->base.complete as the skcipher callback, which is the caller's own completion handler. When the skcipher completes asynchronously, this signals "done" to the caller without executing krb5enc_dispatch_decrypt_hash(), completely bypassing the integrity verification (hash check).

Compare with the encrypt path which correctly uses krb5enc_encrypt_done as an intermediate callback to chain into the hash computation on async completion.

Fix by adding krb5enc_decrypt_done as an intermediate callback that chains into krb5enc_dispatch_decrypt_hash() upon async skcipher completion, matching the encrypt path's callback pattern.

Leer descripción completaMostrar menos

Also fix EBUSY/EINPROGRESS handling throughout: remove krb5enc_request_complete() which incorrectly swallowed EINPROGRESS notifications that must be passed up to callers waiting on backlogged requests, and add missing EBUSY checks in krb5enc_encrypt_ahash_done for the dispatch_encrypt return value.

Unset MAY_BACKLOG on the async completion path so the user won't see back-to-back EINPROGRESS notifications.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vulnerabilidad en crypto kernel (AV:N, PR:N, UI:N) permite bypass de verificación de integridad en descifrado async krb5enc. Integridad comprometida (I:H CVSS) sin autenticación, afectando cifrado en tránsito.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkEncrypt Sensitive Information

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-31719",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "d1775a177f7f38156d541c8a3e3c91eaa6e69699",
              "lessThan": "07cbb1bd424370671814a862913c99a6e1441588",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d1775a177f7f38156d541c8a3e3c91eaa6e69699",
              "lessThan": "e51f42114abbdf47f29dda43e7826be28907fcd2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d1775a177f7f38156d541c8a3e3c91eaa6e69699",
              "lessThan": "3bfbf5f0a99c991769ec562721285df7ab69240b",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "crypto/krb5enc.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.15",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.25",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.0.2",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "crypto/krb5enc.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-05-01T14:16:22.077",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/07cbb1bd424370671814a862913c99a6e1441588",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3bfbf5f0a99c991769ec562721285df7ab69240b",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e51f42114abbdf47f29dda43e7826be28907fcd2",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: krb5enc - fix async decrypt skipping hash verification\n\nkrb5enc_dispatch_decrypt() sets req->base.complete as the skcipher\ncallback, which is the caller's own completion handler. When the\nskcipher completes asynchronously, this signals \"done\" to the caller\nwithout executing krb5enc_dispatch_decrypt_hash(), completely bypassing\nthe integrity verification (hash check).\n\nCompare with the encrypt path which correctly uses\nkrb5enc_encrypt_done as an intermediate callback to chain into the\nhash computation on async completion.\n\nFix by adding krb5enc_decrypt_done as an intermediate callback that\nchains into krb5enc_dispatch_decrypt_hash() upon async skcipher\ncompletion, matching the encrypt path's callback pattern.\n\nAlso fix EBUSY/EINPROGRESS handling throughout: remove\nkrb5enc_request_complete() which incorrectly swallowed EINPROGRESS\nnotifications that must be passed up to callers waiting on backlogged\nrequests, and add missing EBUSY checks in krb5enc_encrypt_ahash_done\nfor the dispatch_encrypt return value.\n\n\nUnset MAY_BACKLOG on the async completion path so the user won't\nsee back-to-back EINPROGRESS notifications."
    }
  ],
  "lastModified": "2026-06-17T10:34:18.260",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F2D3B79E-3EFA-4203-9F11-FF77FD2FBA79",
              "versionEndExcluding": "6.18.25",
              "versionStartIncluding": "6.15"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "1BD58F1E-7C20-4C0D-92A2-FAC5CBFBE8A8",
              "versionEndExcluding": "7.0.2",
              "versionStartIncluding": "6.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}