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FKIE_CVE-2026-23455

Vulnerability from fkie_nvd - Published: 2026-04-03 16:16 - Updated: 2026-07-24 22:10
Severity
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: check for zero length in DecodeQ931() In DecodeQ931(), the UserUserIE code path reads a 16-bit length from the packet, then decrements it by 1 to skip the protocol discriminator byte before passing it to DecodeH323_UserInformation(). If the encoded length is 0, the decrement wraps to -1, which is then passed as a large value to the decoder, leading to an out-of-bounds read. Add a check to ensure len is positive after the decrement.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2121f5fbe88daff0f1fc5bc47d359426c74b86b0Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/65fa92f79677858b14b9e4b7275f26639afe2710Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717bPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60Patch
0b142b55-0307-4c5a-b3c9-f314f3fb7c5ehttps://cert-portal.siemens.com/productcert/html/ssa-019113.html
0b142b55-0307-4c5a-b3c9-f314f3fb7c5ehttps://cert-portal.siemens.com/productcert/html/ssa-082556.html
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
To clipboard 

{
  "affected": [
    {
      "affectedData": [
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          "product": "Linux",
          "programFiles": [
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            },
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
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              "version": "5.10.253",
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              "status": "unaffected",
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              "version": "6.18.20",
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              "version": "6.19.10",
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            },
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              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
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    },
    {
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          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
            }
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          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
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              "status": "affected",
              "version": "V3.1.5",
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            }
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        {
          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
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              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
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          ]
        },
        {
          "defaultStatus": "unknown",
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          "vendor": "Siemens",
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              "status": "affected",
              "version": "V3.1.5",
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          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
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              "lessThan": "*",
              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "vendor": "Siemens",
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              "status": "affected",
              "version": "V3.1.5",
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        },
        {
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          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "vendor": "Siemens",
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              "status": "affected",
              "version": "V3.1.6",
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        {
          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "vendor": "Siemens",
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              "status": "affected",
              "version": "V3.1.5",
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        },
        {
          "defaultStatus": "unknown",
          "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
          "vendor": "Siemens",
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              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unknown",
          "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
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              "status": "affected",
              "version": "V3.1.5",
              "versionType": "custom"
            }
          ]
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      ],
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "CD6C2FEB-75E3-41E6-905C-667A819D083A",
              "versionEndExcluding": "5.10.253",
              "versionStartIncluding": "2.6.17",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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          "negate": false,
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_h323: check for zero length in DecodeQ931()\n\nIn DecodeQ931(), the UserUserIE code path reads a 16-bit length from\nthe packet, then decrements it by 1 to skip the protocol discriminator\nbyte before passing it to DecodeH323_UserInformation(). If the encoded\nlength is 0, the decrement wraps to -1, which is then passed as a\nlarge value to the decoder, leading to an out-of-bounds read.\n\nAdd a check to ensure len is positive after the decrement."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnetfilter: nf_conntrack_h323: comprobaci\u00f3n de longitud cero en DecodeQ931()\n\nEn DecodeQ931(), la ruta de c\u00f3digo UserUserIE lee una longitud de 16 bits del paquete, luego la decrementa en 1 para omitir el byte discriminador del protocolo antes de pasarla a DecodeH323_UserInformation(). Si la longitud codificada es 0, el decremento se ajusta a -1, que luego se pasa como un valor grande al decodificador, lo que lleva a una lectura fuera de l\u00edmites.\n\nSe a\u00f1ade una comprobaci\u00f3n para asegurar que \u0027len\u0027 sea positivo despu\u00e9s del decremento."
    }
  ],
  "id": "CVE-2026-23455",
  "lastModified": "2026-07-24T22:10:00.140",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-04-03T16:16:32.123",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/2121f5fbe88daff0f1fc5bc47d359426c74b86b0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
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      "url": "https://git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/65fa92f79677858b14b9e4b7275f26639afe2710"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60"
    },
    {
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
    },
    {
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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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.