FKIE_CVE-2026-74611

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-10-30 13:20
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
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. 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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1c8629651cb54f7b51db8fc0b1a9944e4a4b0f5e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3c4e21b1bf8e666a1c141e0f5813ece929570deb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3c837266a734e2a22b24d2d567404a501d405835
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/68787940274ec89f41dc91b1a68ee1a16a90735f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/97004f3c17371ee1b259887298711e0604666688
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c71bacacd59166adbea423a04e7474b0e8245b84
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/tls/tls_sw.c",
            "tools/testing/selftests/net/tls.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "97004f3c17371ee1b259887298711e0604666688",
              "status": "affected",
              "version": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "versionType": "git"
            },
            {
              "lessThan": "c71bacacd59166adbea423a04e7474b0e8245b84",
              "status": "affected",
              "version": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "versionType": "git"
            },
            {
              "lessThan": "3c4e21b1bf8e666a1c141e0f5813ece929570deb",
              "status": "affected",
              "version": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "versionType": "git"
            },
            {
              "lessThan": "68787940274ec89f41dc91b1a68ee1a16a90735f",
              "status": "affected",
              "version": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "versionType": "git"
            },
            {
              "lessThan": "3c837266a734e2a22b24d2d567404a501d405835",
              "status": "affected",
              "version": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "versionType": "git"
            },
            {
              "lessThan": "1c8629651cb54f7b51db8fc0b1a9944e4a4b0f5e",
              "status": "affected",
              "version": "ce61327ce989b63c0bd1cc7afee00e218ee696ac",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/tls/tls_sw.c",
            "tools/testing/selftests/net/tls.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.0"
            },
            {
              "lessThan": "6.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "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-\u003emsg_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."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ntls: rx: restaurar msg_iter antes del reintento optimista de TLS 1.3\n\ntls_decrypt_sg() avanza msg -\u003e msg_iter cuando mapea p\u00e1ginas de usuario para la ruta optimista de copia cero de TLS 1.3. Si el registro descifrado resulta no ser datos de aplicaci\u00f3n sin relleno, tls_decrypt_sw() reintenta en un skb del kernel, pero deja el iterador avanzado.\n\nLa copia subsiguiente del skb luego escribe bytes descifrados de nuevo en un punto posterior en los iovecs del llamador mientras que recvmsg() informa solo la longitud posterior al reintento. Un par TLS puede activar esto despu\u00e9s de que el receptor habilite TLS_RX_EXPECT_NO_PAD.\n\nRevertir el iterador por el n\u00famero de bytes consumidos por el mapeo optimista antes de reintentar sin copia cero.\n\nA\u00f1adir una autoprueba que env\u00eda un registro de control TLS 1.3 con TLS_RX_EXPECT_NO_PAD habilitado y verifica que recvmsg() no sobrescribe iovecs posteriores m\u00e1s all\u00e1 de la longitud devuelta."
    }
  ],
  "id": "CVE-2026-74611",
  "lastModified": "2026-10-30T13:20:03.240",
  "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"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-74611",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-16T19:02:18.342764Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-22T16:16:33.670",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1c8629651cb54f7b51db8fc0b1a9944e4a4b0f5e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3c4e21b1bf8e666a1c141e0f5813ece929570deb"
    },
    {
      "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",
      "url": "https://git.kernel.org/stable/c/97004f3c17371ee1b259887298711e0604666688"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c71bacacd59166adbea423a04e7474b0e8245b84"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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