FKIE_CVE-2026-23943

Vulnerability from fkie_nvd - Published: 2026-03-13 19:54 - Updated: 2026-05-21 15:22
Severity
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Summary
Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion. The SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS. Two compression algorithms are affected: * zlib: Activates immediately after key exchange, enabling unauthenticated attacks * zlib@openssh.com: Activates post-authentication, enabling authenticated attacks Each SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments. This vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4. This issue affects OTP from OTP 17.0 until OTP 28.4.1, 27.3.4.9 and 26.2.5.18 corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14.
References
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://cna.erlef.org/cves/CVE-2026-23943.htmlVendor Advisory
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/erlang/otp/commit/0c1c04b191f6ab940e8fcfabce39eb5a8a6440a4Patch
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/erlang/otp/commit/43a87b949bdff12d629a8c34146711d9da93b1b1Patch
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/erlang/otp/commit/93073c3bd338c60cd2bae715ce6a1d4ffc1a8fd3Patch
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/erlang/otp/security/advisories/GHSA-c836-qprm-jw9rVendor Advisory
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://osv.dev/vulnerability/EEF-CVE-2026-23943Third Party Advisory
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://www.erlang.org/doc/system/versions.html#order-of-versionsProduct
Impacted products
Vendor Product Version
erlang erlang\/otp *
erlang erlang\/otp *
erlang erlang\/otp *
erlang erlang\/ssh *
erlang erlang\/ssh *
erlang erlang\/ssh *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6241E245-67D2-4FA6-83FE-4E9A4A07B3D1",
              "versionEndExcluding": "26.2.5.18",
              "versionStartIncluding": "17.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "BE60BA92-431E-4DE3-A1C1-E8976E3A6BA7",
              "versionEndExcluding": "27.3.4.9",
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              "vulnerable": true
            },
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              "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B8D9E80B-CA20-423A-A1A8-DEBB99D82BDB",
              "versionEndExcluding": "28.4.1",
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            },
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              "matchCriteriaId": "24FD89BF-28BB-4432-9FDA-F0D84B5F716C",
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              "vulnerable": true
            },
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              "criteria": "cpe:2.3:a:erlang:erlang\\/ssh:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "C0BFA1FA-14CC-4A47-A6A3-2572BA686367",
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            },
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              "matchCriteriaId": "0ABFC1FB-435C-414A-BF43-B119730E3DCE",
              "versionEndIncluding": "5.5.1",
              "versionStartIncluding": "5.5",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion.\n\nThe SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS.\n\nTwo compression algorithms are affected:\n\n* zlib: Activates immediately after key exchange, enabling unauthenticated attacks\n* zlib@openssh.com: Activates post-authentication, enabling authenticated attacks\n\nEach SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments.\n\nThis vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4.\n\nThis issue affects OTP from OTP 17.0 until OTP 28.4.1, 27.3.4.9 and 26.2.5.18 corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14."
    },
    {
      "lang": "es",
      "value": "La vulnerabilidad de Manejo Inadecuado de Datos Altamente Comprimidos (Bomba de Compresi\u00f3n) en Erlang OTP ssh (m\u00f3dulos ssh_transport) permite la denegaci\u00f3n de servicio mediante el agotamiento de recursos.\n\nLa capa de transporte SSH anuncia la compresi\u00f3n zlib heredada por defecto e infla cargas \u00fatiles controladas por el atacante pre-autenticaci\u00f3n sin ning\u00fan l\u00edmite de tama\u00f1o, lo que permite una DoS fiable por agotamiento de memoria.\n\nDos algoritmos de compresi\u00f3n se ven afectados:\n\n* zlib: Se activa inmediatamente despu\u00e9s del intercambio de claves, lo que permite ataques no autenticados\n* zlib@openssh.com: Se activa post-autenticaci\u00f3n, lo que permite ataques autenticados\n\nCada paquete SSH puede descomprimir ~255 MB de 256 KB de datos en la red (relaci\u00f3n de amplificaci\u00f3n de 1029:1). M\u00faltiples paquetes pueden agotar r\u00e1pidamente la memoria disponible, causando eliminaciones por OOM en entornos con memoria limitada.\n\nEsta vulnerabilidad est\u00e1 asociada con los archivos de programa lib/ssh/src/ssh_transport.erl y las rutinas de programa ssh_transport:decompress/2, ssh_transport:handle_packet_part/4.\n\nEste problema afecta a OTP desde OTP 17.0 hasta OTP 28.4.1, 27.3.4.9 y 26.2.5.18, lo que corresponde a ssh desde 3.0.1 hasta 5.5.1, 5.2.11.6 y 5.1.4.14."
    }
  ],
  "id": "CVE-2026-23943",
  "lastModified": "2026-05-21T15:22:36.017",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "LOW",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-03-13T19:54:15.783",
  "references": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://cna.erlef.org/cves/CVE-2026-23943.html"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
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      "url": "https://github.com/erlang/otp/commit/0c1c04b191f6ab940e8fcfabce39eb5a8a6440a4"
    },
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    },
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      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "tags": [
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    },
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    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "tags": [
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      ],
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-23943"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "tags": [
        "Product"
      ],
      "url": "https://www.erlang.org/doc/system/versions.html#order-of-versions"
    }
  ],
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-409"
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary"
    }
  ]
}


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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

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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.