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GHSA-XJJ6-F33Q-929C

Vulnerability from github – Published: 2026-10-23 22:14 – Updated: 2026-10-23 22:14

Summary

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

Details

Impact

undici's fetch() 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 (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. The early close then surfaces a content-length mismatch on that orphaned internal 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. undici 6.x, 7.x, and 8.x are affected.

Patches

Upgrade to 6.29.1, 7.30.1, or 8.12.2. undici now validates the content-encoding chain before creating the internal body stream and aborts the response when the limit is exceeded, so no error can surface on an orphaned stream.

Workarounds

None.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "undici"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.23.0"
            },
            {
              "fixed": "6.29.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "undici"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.18.0"
            },
            {
              "fixed": "7.30.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "undici"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.12.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-109869"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-248",
      "CWE-459"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-23T22:14:31Z",
    "nvd_published_at": "2026-10-15T19:17:21Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nundici\u0027s `fetch()` 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 (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. The early close then surfaces a content-length mismatch on that orphaned internal 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. undici 6.x, 7.x, and 8.x are affected.\n\n### Patches\n\nUpgrade to `6.29.1`, `7.30.1`, or `8.12.2`. undici now validates the content-encoding chain before creating the internal body stream and aborts the response when the limit is exceeded, so no error can surface on an orphaned stream.\n\n### Workarounds\n\nNone.",
  "id": "GHSA-xjj6-f33q-929c",
  "modified": "2026-10-23T22:14:31Z",
  "published": "2026-10-23T22:14:31Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/security/advisories/GHSA-xjj6-f33q-929c"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109869"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/commit/07ded4941b1e72afec862958c3b8ddf468f3b429"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/commit/1325a87dfb3492f8e87e6b0a84b3bda4e82e3436"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/commit/b5084c7dc239172d75c336b1cd51ddac023938a5"
    },
    {
      "type": "WEB",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nodejs/undici"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/releases/tag/v6.29.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/releases/tag/v7.30.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/releases/tag/v8.12.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "undici vulnerable to Denial of Service via unhandled error on excessive content-encodings"
}

CVE-2026-109869 (GCVE-0-2026-109869)

Vulnerability from cvelistv5 – Published: 2026-10-15 18:08 – Updated: 2026-10-16 20:06

Title

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

Summary

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.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-16 20:05 UTC

CWE

CWE-248 - Uncaught Exception
CWE-459 - Incomplete Cleanup

Assigner

openjs CNA under the redhat root

CNA scorecard C 65/100 over 118 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/nodejs/undici/security/advisor…
https://cna.openjsf.org/security-advisories.html

Impacted products

1 product

Vendor	Product	Version
undici	undici	Affected: 6.23.0 , < 6.29.1 (semver) Unaffected: 6.29.1 (semver) Affected: 7.18.0 , < 7.30.1 (semver) Unaffected: 7.30.1 (semver) Affected: 8.0.0 , < 8.12.2 (semver) Unaffected: 8.12.2 (semver)

Credits

hanityx mcollina UlisesGascon

Show details on NVD website

JSON

To clipboard

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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.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
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