Vulnerability-Lookup

CVE-2026-2581 (GCVE-0-2026-2581)

Vulnerability from cvelistv5 – Published: 2026-03-12 20:13 – Updated: 2026-03-13 18:04

Title

undici is vulnerable to Unbounded Memory Consumption in in Undici's DeduplicationHandler via Response Buffering leads to DoS

Summary

This is an uncontrolled resource consumption vulnerability (CWE-400) that can lead to Denial of Service (DoS). In vulnerable Undici versions, when interceptors.deduplicate() is enabled, response data for deduplicated requests could be accumulated in memory for downstream handlers. An attacker-controlled or untrusted upstream endpoint can exploit this with large/chunked responses and concurrent identical requests, causing high memory usage and potential OOM process termination. Impacted users are applications that use Undici’s deduplication interceptor against endpoints that may produce large or long-lived response bodies. PatchesThe issue has been patched by changing deduplication behavior to stream response chunks to downstream handlers as they arrive (instead of full-body accumulation), and by preventing late deduplication when body streaming has already started. Users should upgrade to the first official Undici (and Node.js, where applicable) releases that include this patch.

Severity ?

5.9 (Medium)


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

CWE

CWE-770 - Allocation of resources without limits or throttling

Assigner

openjs

References

URL

Tags

	https://github.com/nodejs/undici/security/advisor…
	https://hackerone.com/reports/3513473
	https://cna.openjsf.org/security-advisories.html

Impacted products

	Vendor	Product	Version
	undici	undici	Affected: < 6.24.0; 7.0.0 < 7.24.0 Unaffected: 6.24.0: 7.24.0

Credits

Matteo Collina Ulises Gascón Adnan Jakati

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-2581

Vulnerability from fkie_nvd - Published: 2026-03-12 21:16 - Updated: 2026-03-13 20:06

Severity ?

5.9 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

References

	URL	Tags
	ce714d77-add3-4f53-aff5-83d477b104bb	https://cna.openjsf.org/security-advisories.html
	ce714d77-add3-4f53-aff5-83d477b104bb	https://github.com/nodejs/undici/security/advisories/GHSA-phc3-fgpg-7m6h
	ce714d77-add3-4f53-aff5-83d477b104bb	https://hackerone.com/reports/3513473

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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GHSA-PHC3-FGPG-7M6H

Vulnerability from github – Published: 2026-03-13 20:37 – Updated: 2026-03-13 20:37

Summary

Undici has Unbounded Memory Consumption in its DeduplicationHandler via Response Buffering that leads to DoS

Details

Impact

This is an uncontrolled resource consumption vulnerability (CWE-400) that can lead to Denial of Service (DoS).

In vulnerable Undici versions, when interceptors.deduplicate() is enabled, response data for deduplicated requests could be accumulated in memory for downstream handlers. An attacker-controlled or untrusted upstream endpoint can exploit this with large/chunked responses and concurrent identical requests, causing high memory usage and potential OOM process termination.

Impacted users are applications that use Undici’s deduplication interceptor against endpoints that may produce large or long-lived response bodies.

Patches

The issue has been patched by changing deduplication behavior to stream response chunks to downstream handlers as they arrive (instead of full-body accumulation), and by preventing late deduplication when body streaming has already started.

Users should upgrade to the first official Undici (and Node.js, where applicable) releases that include this patch.

Workarounds

If upgrading immediately is not possible:

Disable interceptors.deduplicate() for affected clients/routes.
Use skipHeaderNames with a marker header to force high-risk requests to bypass deduplication.
Avoid concurrent identical requests to untrusted endpoints that may return very large/chunked bodies.
Apply upstream/proxy response-size and timeout limits.

Severity ?

5.9 (Medium)


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

Show details on source website

JSON

To clipboard

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    "severity": "MODERATE"
  },
  "details": "## Impact\nThis is an uncontrolled resource consumption vulnerability (CWE-400) that can lead to Denial of Service (DoS).\n\nIn vulnerable Undici versions, when `interceptors.deduplicate()` is enabled, response data for deduplicated requests could be accumulated in memory for downstream handlers. An attacker-controlled or untrusted upstream endpoint can exploit this with large/chunked responses and concurrent identical requests, causing high memory usage and potential OOM process termination.\n\nImpacted users are applications that use Undici\u2019s deduplication interceptor against endpoints that may produce large or long-lived response bodies.\n\n## Patches\n\nThe issue has been patched by changing deduplication behavior to stream response chunks to downstream handlers as they arrive (instead of full-body accumulation), and by preventing late deduplication when body streaming has already started.\n\nUsers should upgrade to the first official Undici (and Node.js, where applicable) releases that include this patch.\n\n## Workarounds\nIf upgrading immediately is not possible:\n\n- Disable `interceptors.deduplicate()` for affected clients/routes.\n- Use `skipHeaderNames` with a marker header to force high-risk requests to bypass deduplication.\n- Avoid concurrent identical requests to untrusted endpoints that may return very large/chunked bodies.\n- Apply upstream/proxy response-size and timeout limits.",
  "id": "GHSA-phc3-fgpg-7m6h",
  "modified": "2026-03-13T20:37:58Z",
  "published": "2026-03-13T20:37:58Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/security/advisories/GHSA-phc3-fgpg-7m6h"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2581"
    },
    {
      "type": "WEB",
      "url": "https://hackerone.com/reports/3513473"
    },
    {
      "type": "WEB",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nodejs/undici"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Undici has Unbounded Memory Consumption in its DeduplicationHandler via Response Buffering that leads to DoS"
}

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.

Action not permitted

CVE-2026-2581 (GCVE-0-2026-2581)

FKIE_CVE-2026-2581

GHSA-PHC3-FGPG-7M6H

Impact

Patches

Workarounds

Tags

Sightings

Nomenclature