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undici vulnerable to Denial of Service via unhandled error on excessive content-encodings

Type: advisorySource: Official CVE List1 source record

undici is an HTTP client library for Node.js. In versions 6.23.0 through 6.29.0, 7.18.0 through 7.30.0, and 8.0.0 through 8.12.1, its fetch() implementation crashes the Node.js process when a malicious server returns a response with more than five content codings and closes the connection before sending the body. undici rejects such responses because of a content-encoding limit, but it created the internal response stream before that check and returned without attaching an error listener or aborting the request, so the early close surfaces a content-length mismatch on the orphaned stream, which Node.js treats as an unhandled error and terminates the process. A remote, unauthenticated server can trigger this with a single response, even when the application correctly catches the fetch() rejection, resulting in a denial of service. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, and users should upgrade to one of those versions or later. There is no workaround.

Announced Group revision 1
Original source ↗

CVE-2026-109869

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-109869

undici

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "vendor": "undici",
    "product": "undici",
    "versions": [
      {
        "status": "affected",
        "version": "6.23.0",
        "lessThan": "6.29.1",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.29.1",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "7.18.0",
        "lessThan": "7.30.1",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "7.30.1",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "8.0.0",
        "lessThan": "8.12.2",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "8.12.2",
        "versionType": "semver"
      }
    ],
    "packageURL": "pkg:npm/undici",
    "defaultStatus": "unaffected"
  }
]
Related CVEs
CVE-2026-109869

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#34421 · Revision 1
Added to Heist Feed
Publisher date
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