CVE-2026-1526 (GCVE-0-2026-1526)

Vulnerability from cvelistv5 – Published: 2026-03-12 20:08 – Updated: 2026-03-13 18:04
VLAI?
Title
undici is vulnerable to Unbounded Memory Consumption in undici WebSocket permessage-deflate Decompression
Summary
The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a "decompression bomb") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive. The vulnerability exists in the PerMessageDeflate.decompress() method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.
Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-409 - Improper handling of highly compressed data (data amplification)
Assigner
References
Impacted products
Vendor Product Version
undici undici Affected: < 6.24.0; 7.0.0 < 7.24.0
Unaffected: 6.24.0: 7.24.0
Create a notification for this product.
Credits
Matteo Collina Ulises Gascón HO9
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-1526",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-13T18:04:06.608247Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-13T18:04:20.683Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://github.com/nodejs/undici/",
          "defaultStatus": "unaffected",
          "packageName": "undici",
          "product": "undici",
          "repo": "https://github.com/nodejs/undici/",
          "vendor": "undici",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.24.0; 7.0.0 \u003c 7.24.0"
            },
            {
              "status": "unaffected",
              "version": "6.24.0: 7.24.0"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Matteo Collina"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Ulises Gasc\u00f3n"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "HO9"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eThe undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a \"decompression bomb\") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive.\u003c/p\u003e\u003cp\u003eThe vulnerability exists in the\u0026nbsp;\u003ccode\u003ePerMessageDeflate.decompress()\u003c/code\u003e\u0026nbsp;method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.\u003c/p\u003e"
            }
          ],
          "value": "The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a \"decompression bomb\") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive.\n\nThe vulnerability exists in the\u00a0PerMessageDeflate.decompress()\u00a0method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "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:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-409",
              "description": "CWE-409 Improper handling of highly compressed data (data amplification)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-12T20:08:05.950Z",
        "orgId": "ce714d77-add3-4f53-aff5-83d477b104bb",
        "shortName": "openjs"
      },
      "references": [
        {
          "url": "https://github.com/nodejs/undici/security/advisories/GHSA-vrm6-8vpv-qv8q"
        },
        {
          "url": "https://hackerone.com/reports/3481206"
        },
        {
          "url": "https://cna.openjsf.org/security-advisories.html"
        },
        {
          "url": "https://datatracker.ietf.org/doc/html/rfc7692"
        }
      ],
      "source": {
        "advisory": "GHSA-vrm6-8vpv-qv8q",
        "discovery": "EXTERNAL"
      },
      "title": "undici is vulnerable to Unbounded Memory Consumption in undici WebSocket permessage-deflate Decompression",
      "x_generator": {
        "engine": "Vulnogram 1.0.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb",
    "assignerShortName": "openjs",
    "cveId": "CVE-2026-1526",
    "datePublished": "2026-03-12T20:08:05.950Z",
    "dateReserved": "2026-01-28T12:05:07.017Z",
    "dateUpdated": "2026-03-13T18:04:20.683Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-1526\",\"sourceIdentifier\":\"ce714d77-add3-4f53-aff5-83d477b104bb\",\"published\":\"2026-03-12T21:16:23.933\",\"lastModified\":\"2026-03-13T20:06:54.667\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a \\\"decompression bomb\\\") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive.\\n\\nThe vulnerability exists in the\u00a0PerMessageDeflate.decompress()\u00a0method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.\"},{\"lang\":\"es\",\"value\":\"El cliente WebSocket undici es vulnerable a un ataque de denegaci\u00f3n de servicio a trav\u00e9s de un consumo de memoria ilimitado durante la descompresi\u00f3n permessage-deflate. Cuando una conexi\u00f3n WebSocket negocia la extensi\u00f3n permessage-deflate, el cliente descomprime las tramas comprimidas entrantes sin imponer ning\u00fan l\u00edmite en el tama\u00f1o de los datos descomprimidos. Un servidor WebSocket malicioso puede enviar una peque\u00f1a trama comprimida (una \u0027bomba de descompresi\u00f3n\u0027) que se expande a un tama\u00f1o extremadamente grande en memoria, causando que el proceso de Node.js agote la memoria disponible y colapse o deje de responder.\\n\\nLa vulnerabilidad existe en el m\u00e9todo PerMessageDeflate.decompress(), que acumula todos los fragmentos descomprimidos en memoria y los concatena en un \u00fanico Buffer sin verificar si el tama\u00f1o total excede un umbral seguro.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"ce714d77-add3-4f53-aff5-83d477b104bb\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"ce714d77-add3-4f53-aff5-83d477b104bb\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-409\"}]}],\"references\":[{\"url\":\"https://cna.openjsf.org/security-advisories.html\",\"source\":\"ce714d77-add3-4f53-aff5-83d477b104bb\"},{\"url\":\"https://datatracker.ietf.org/doc/html/rfc7692\",\"source\":\"ce714d77-add3-4f53-aff5-83d477b104bb\"},{\"url\":\"https://github.com/nodejs/undici/security/advisories/GHSA-vrm6-8vpv-qv8q\",\"source\":\"ce714d77-add3-4f53-aff5-83d477b104bb\"},{\"url\":\"https://hackerone.com/reports/3481206\",\"source\":\"ce714d77-add3-4f53-aff5-83d477b104bb\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-1526\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-13T18:04:06.608247Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-13T18:04:13.626Z\"}}], \"cna\": {\"title\": \"undici is vulnerable to Unbounded Memory Consumption in undici WebSocket permessage-deflate Decompression\", \"source\": {\"advisory\": \"GHSA-vrm6-8vpv-qv8q\", \"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"remediation developer\", \"value\": \"Matteo Collina\"}, {\"lang\": \"en\", \"type\": \"remediation developer\", \"value\": \"Ulises Gasc\\u00f3n\"}, {\"lang\": \"en\", \"type\": \"finder\", \"value\": \"HO9\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"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:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"repo\": \"https://github.com/nodejs/undici/\", \"vendor\": \"undici\", \"product\": \"undici\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 6.24.0; 7.0.0 \u003c 7.24.0\"}, {\"status\": \"unaffected\", \"version\": \"6.24.0: 7.24.0\"}], \"packageName\": \"undici\", \"collectionURL\": \"https://github.com/nodejs/undici/\", \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://github.com/nodejs/undici/security/advisories/GHSA-vrm6-8vpv-qv8q\"}, {\"url\": \"https://hackerone.com/reports/3481206\"}, {\"url\": \"https://cna.openjsf.org/security-advisories.html\"}, {\"url\": \"https://datatracker.ietf.org/doc/html/rfc7692\"}], \"x_generator\": {\"engine\": \"Vulnogram 1.0.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a \\\"decompression bomb\\\") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive.\\n\\nThe vulnerability exists in the\\u00a0PerMessageDeflate.decompress()\\u00a0method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eThe undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a \\\"decompression bomb\\\") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive.\u003c/p\u003e\u003cp\u003eThe vulnerability exists in the\u0026nbsp;\u003ccode\u003ePerMessageDeflate.decompress()\u003c/code\u003e\u0026nbsp;method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.\u003c/p\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-409\", \"description\": \"CWE-409 Improper handling of highly compressed data (data amplification)\"}]}], \"providerMetadata\": {\"orgId\": \"ce714d77-add3-4f53-aff5-83d477b104bb\", \"shortName\": \"openjs\", \"dateUpdated\": \"2026-03-12T20:08:05.950Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-1526\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-03-13T18:04:20.683Z\", \"dateReserved\": \"2026-01-28T12:05:07.017Z\", \"assignerOrgId\": \"ce714d77-add3-4f53-aff5-83d477b104bb\", \"datePublished\": \"2026-03-12T20:08:05.950Z\", \"assignerShortName\": \"openjs\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

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.