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node-undici — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-CVE-2026-85024

undici bundles a WebSocket client whose permessage-deflate size-limit cleanup removes all listeners from the internal zlib inflate stream, including its error listener, while that stream can still emit. When a remote peer sends a compressed payload that crosses the built-in 128 MiB decompressed-payload limit and then contains a malformed DEFLATE byte, the inflate stream emits a data error with no listener attached, which Node.js treats as a fatal unhandled error and terminates the entire process. Exploitation is remote and unauthenticated, requires no application mistake, and is asymmetric, since roughly 130 KB on the wire expands past the limit and crashes the process, and reconnecting can repeat the crash. This affects undici versions from 6.25.0 up to 6.28.1, from 7.28.0 up to 7.29.1, and from 8.1.0 up to 8.10.2. Users should upgrade to undici 6.28.1, 7.29.1, or 8.10.2.

Products
node-undici
Affected versions
5.22.1+dfsg1+~cs20.10.10.2-1ubuntu1, 5.26.3+dfsg1+~cs23.10.12-2, 7.16.0+dfsg+~cs3.2.0-2, 7.18.2+dfsg+~cs3.2.0-1, 7.18.2+dfsg+~cs3.2.0-1build1, 7.24.6+dfsg+~cs3.2.0-3, 7.3.0+dfsg1+~cs24.12.11-2, 8.5.0+dfsg+~cs3.2.0-2, 8.5.0+dfsg+~cs3.2.0-3, 8.9.0+dfsg+~cs3.2.0-1
Fixed versions
Not specified
CVEs
CVE-2026-85024
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 03:23 UTC · Revision 1

Source evidence

UBUNTU-CVE-2026-85024

core-osv · Original source

Published 4 Sept 2026, 17:17 UTC

undici bundles a WebSocket client whose permessage-deflate size-limit cleanup removes all listeners from the internal zlib inflate stream, including its error listener, while that stream can still emit. When a remote peer sends a compressed payload that crosses the built-in 128 MiB decompressed-payload limit and then contains a malformed DEFLATE byte, the inflate stream emits a data error with no listener attached, which Node.js treats as a fatal unhandled error and terminates the entire process. Exploitation is remote and unauthenticated, requires no application mistake, and is asymmetric, since roughly 130 KB on the wire expands past the limit and crashes the process, and reconnecting can repeat the crash. This affects undici versions from 6.25.0 up to 6.28.1, from 7.28.0 up to 7.29.1, and from 8.1.0 up to 8.10.2. Users should upgrade to undici 6.28.1, 7.29.1, or 8.10.2.

osv:UBUNTU-CVE-2026-85024

node-undici

Fixed versions: Not specified

node-undici

Fixed versions: Not specified

node-undici

Fixed versions: Not specified

Complete source record
{
  "id": "cfb60aecf3271139424ce2b7e6ffdc8b55e63142df9555d2d696429b16af78be",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-85024",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-85024",
    "summary": "undici bundles a WebSocket client whose permessage-deflate size-limit cleanup removes all listeners from the internal zlib inflate stream, including its error listener, while that stream can still emit. When a remote peer sends a compressed payload that crosses the built-in 128 MiB decompressed-payload limit and then contains a malformed DEFLATE byte, the inflate stream emits a data error with no listener attached, which Node.js treats as a fatal unhandled error and terminates the entire process. Exploitation is remote and unauthenticated, requires no application mistake, and is asymmetric, since roughly 130 KB on the wire expands past the limit and crashes the process, and reconnecting can repeat the crash. This affects undici versions from 6.25.0 up to 6.28.1, from 7.28.0 up to 7.29.1, and from 8.1.0 up to 8.10.2. Users should upgrade to undici 6.28.1, 7.29.1, or 8.10.2.",
    "evidence": "osv:UBUNTU-CVE-2026-85024",
    "products": [
      {
        "name": {
          "value": "node-undici",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "5.22.1+dfsg1+~cs20.10.10.2-1ubuntu1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "5.26.3+dfsg1+~cs23.10.12-2",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "node-undici",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "7.18.2+dfsg+~cs3.2.0-1build1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "7.24.6+dfsg+~cs3.2.0-3",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "8.5.0+dfsg+~cs3.2.0-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "8.5.0+dfsg+~cs3.2.0-3",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "8.9.0+dfsg+~cs3.2.0-1",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "node-undici",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "7.3.0+dfsg1+~cs24.12.11-2",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "7.16.0+dfsg+~cs3.2.0-2",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "7.18.2+dfsg+~cs3.2.0-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "7.18.2+dfsg+~cs3.2.0-1build1",
            "evidence": "/affected/2/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-85024",
      "aliases": [
        "UBUNTU-CVE-2026-85024"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "node-undici",
            "purl": "pkg:deb/ubuntu/node-undici?arch=source&distro=noble",
            "ecosystem": "Ubuntu:24.04:LTS"
          },
          "versions": [
            "5.22.1+dfsg1+~cs20.10.10.2-1ubuntu1",
            "5.26.3+dfsg1+~cs23.10.12-2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85024.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "node-llhttp",
                "binary_version": "9.1.3~5.26.3+dfsg1+~cs23.10.12-2"
              },
              {
                "binary_name": "node-undici",
                "binary_version": "5.26.3+dfsg1+~cs23.10.12-2"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "node-undici",
            "purl": "pkg:deb/ubuntu/node-undici?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "7.18.2+dfsg+~cs3.2.0-1build1",
            "7.24.6+dfsg+~cs3.2.0-3",
            "8.5.0+dfsg+~cs3.2.0-2",
            "8.5.0+dfsg+~cs3.2.0-3",
            "8.9.0+dfsg+~cs3.2.0-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85024.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "node-undici",
                "binary_version": "8.9.0+dfsg+~cs3.2.0-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "node-undici",
            "purl": "pkg:deb/ubuntu/node-undici?arch=source&distro=resolute",
            "ecosystem": "Ubuntu:26.04:LTS"
          },
          "versions": [
            "7.3.0+dfsg1+~cs24.12.11-2",
            "7.16.0+dfsg+~cs3.2.0-2",
            "7.18.2+dfsg+~cs3.2.0-1",
            "7.18.2+dfsg+~cs3.2.0-1build1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85024.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "node-undici",
                "binary_version": "7.18.2+dfsg+~cs3.2.0-1build1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T13:01:13.120932350Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-85024"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-85024",
        "https://www.cve.org/CVERecord?id=CVE-2026-85024",
        "https://github.com/nodejs/undici/security/advisories/GHSA-3wwx-pv8p-q78v"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-85024",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 361276,
  "published_at": "2026-09-04T17:17:00+00:00"
}