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CVE-2026-74611

Estado: RecibidaCrítica (9.8)—

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

tls: rx: restore msg_iter before TLS 1.3 optimistic retry

tls_decrypt_sg() advances msg->msg_iter when it maps user pages for the optimistic TLS 1.3 zero-copy path. If the decrypted record turns out not to be unpadded application data, tls_decrypt_sw() retries into a kernel skb, but leaves the iterator advanced.

The subsequent copy from the skb then writes decrypted bytes again at a later point in the caller iovecs while recvmsg() reports only the post-retry length. A TLS peer can trigger this after the receiver enables TLS_RX_EXPECT_NO_PAD.

Leer descripción completaMostrar menos

Revert the iterator by the number of bytes consumed by the optimistic mapping before retrying without zero-copy.

Add a selftest which sends a TLS 1.3 control record with TLS_RX_EXPECT_NO_PAD enabled and verifies that recvmsg() does not overwrite later iovecs beyond the returned length.

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 remota sin autenticación (AV:N/PR:N/UI:N) en kernel Linux que corrompe iteradores de memoria en TLS 1.3, permitiendo sobrescritura de búferes en aplicaciones user-space y posible denegación de servicio.

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 ScanningRestrict File and Directory PermissionsPrivileged Account ManagementRemote Data StorageNetwork Segmentation

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux KernelAI

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-74611",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "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": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "lessThan": "68787940274ec89f41dc91b1a68ee1a16a90735f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "lessThan": "3c837266a734e2a22b24d2d567404a501d405835",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "lessThan": "1c8629651cb54f7b51db8fc0b1a9944e4a4b0f5e",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/tls/tls_sw.c",
            "tools/testing/selftests/net/tls.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.0"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/tls/tls_sw.c",
            "tools/testing/selftests/net/tls.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-22T16:16:33.670",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1c8629651cb54f7b51db8fc0b1a9944e4a4b0f5e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3c837266a734e2a22b24d2d567404a501d405835",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/68787940274ec89f41dc91b1a68ee1a16a90735f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntls: rx: restore msg_iter before TLS 1.3 optimistic retry\n\ntls_decrypt_sg() advances msg->msg_iter when it maps user pages for\nthe optimistic TLS 1.3 zero-copy path. If the decrypted record turns\nout not to be unpadded application data, tls_decrypt_sw() retries into\na kernel skb, but leaves the iterator advanced.\n\nThe subsequent copy from the skb then writes decrypted bytes again at\na later point in the caller iovecs while recvmsg() reports only the\npost-retry length. A TLS peer can trigger this after the receiver\nenables TLS_RX_EXPECT_NO_PAD.\n\nRevert the iterator by the number of bytes consumed by the optimistic\nmapping before retrying without zero-copy.\n\nAdd a selftest which sends a TLS 1.3 control record with\nTLS_RX_EXPECT_NO_PAD enabled and verifies that recvmsg() does not\noverwrite later iovecs beyond the returned length."
    }
  ],
  "lastModified": "2026-08-25T06:18:38.440",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}