Vulnerability-Lookup

UBUNTU-CVE-2026-9675 (CVE-2026-9675)

Vulnerability from osv_ubuntu – Published: 2026-06-17 17:17 – Updated: 2026-06-24 08:58 – Source website

Details

Impact: The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service. Affected applications are those using the undici WebSocket client (new WebSocket(...)) that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint. This is a regression specific to undici 8.1.0. The 6.25.0 line shipped the equivalent cumulative check from the start and is unaffected. The 7.x line never had the maxPayloadSize feature and is also unaffected. Patches: Upgrade to undici >= 8.5.0. Workarounds: No workaround is available. The fix must be applied through an upgrade.

Severity

7.5 (High)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-9675	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-9675	REPORT
	https://github.com/nodejs/undici/security/advisor…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "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"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "node-undici",
        "purl": "pkg:deb/ubuntu/node-undici@5.26.3+dfsg1+~cs23.10.12-2?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.22.1+dfsg1+~cs20.10.10.2-1ubuntu1",
        "5.26.3+dfsg1+~cs23.10.12-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libllhttp9.2",
            "binary_version": "9.2.1~7.3.0+dfsg1+~cs24.12.11-2"
          },
          {
            "binary_name": "node-llhttp",
            "binary_version": "9.2.1~7.3.0+dfsg1+~cs24.12.11-2"
          },
          {
            "binary_name": "node-undici",
            "binary_version": "7.3.0+dfsg1+~cs24.12.11-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "node-undici",
        "purl": "pkg:deb/ubuntu/node-undici@7.3.0+dfsg1+~cs24.12.11-2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.3.0+dfsg1+~cs24.12.11-1",
        "7.3.0+dfsg1+~cs24.12.11-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "node-undici",
            "binary_version": "7.18.2+dfsg+~cs3.2.0-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "node-undici",
        "purl": "pkg:deb/ubuntu/node-undici@7.18.2+dfsg+~cs3.2.0-1build1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "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"
      ]
    }
  ],
  "aliases": [],
  "details": "Impact: The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service. Affected applications are those using the undici WebSocket client (new WebSocket(...)) that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint. This is a regression specific to undici 8.1.0. The 6.25.0 line shipped the equivalent cumulative check from the start and is unaffected. The 7.x line never had the maxPayloadSize feature and is also unaffected. Patches: Upgrade to undici \u003e= 8.5.0. Workarounds: No workaround is available. The fix must be applied through an upgrade.",
  "id": "UBUNTU-CVE-2026-9675",
  "modified": "2026-06-24T08:58:46Z",
  "published": "2026-06-17T17:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-9675"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-9675"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/nodejs/undici/security/advisories/GHSA-38rv-x7px-6hhq"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-9675"
  ]
}

CVE-2026-9675 (GCVE-0-2026-9675)

Vulnerability from cvelistv5 – Published: 2026-06-17 16:20 – Updated: 2026-06-17 17:29

Title

undici WebSocket client vulnerable to denial of service via cumulative fragment bypass

Summary

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 2026-06-17 17:29 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption
CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

openjs redhat root

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: 8.0.0 , < 8.5.0 (semver) Unaffected: 8.5.0 (semver)

Credits

mauriceng98 Str1ckl4nd mcollina UlisesGascon lzhou1110 Zyy0530

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-9675",
                "options": [
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                  },
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                    "Technical Impact": "partial"
                  }
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                "role": "CISA Coordinator",
                "timestamp": "2026-06-17T17:29:24.751635Z",
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          "supportingMedia": [
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            }
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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.

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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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UBUNTU-CVE-2026-9675 (CVE-2026-9675)

CVE-2026-9675 (GCVE-0-2026-9675)

Tags

Sightings

Nomenclature

Related by attack behaviour