CVE-2026-85152: Undici Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-vp8m-p9jh-q5pm
CVSS 7.4
CWE-346
Published
Advisory Summary

CVE-2026-85152 is a HIGH (CVSS 7.4) remote code execution vulnerability (CWE-346: Origin Validation Error) affecting Undici libraries in the npm ecosystem. The issue involves undici vulnerable to cross-origin cache poisoning via missing origin isolation in interceptors. Remediation is available by upgrading affected packages to version 8.10.2.

CVE-2026-85152 at a Glance

CVE Identifier CVE-2026-85152
GHSA Identifier GHSA-vp8m-p9jh-q5pm
Severity HIGH
CVSS v3.1 Base Score 7.4
CWE Classification CWE-346: Origin Validation Error
Affected Product Undici
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-85152

To remediate this vulnerability, upgrade all affected Undici dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

undici fixed: 8.10.2
npm install undici@8.10.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

npm ls undici

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-85152, inspect your project dependencies using npm:

npm ls undici

Analyze the terminal output to locate any version of Undici in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 8.10.2), your application is affected.

Note: The npm ls undici command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-346: Origin Validation Error, where the product does not properly verify that the source of data or communication is valid. In Undici, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Impact When `interceptors.cache()` or `interceptors.deduplicate()` is used with a dispatcher that does not carry a single authoritative origin, or when a request supplies its own `origin`, undici builds the cache and deduplication keys without the actual destination origin. If a cache store or interceptor instance is shared across more than one origin, otherwise-identical requests to different origins are keyed together. An attacker who controls the response from one origin can then have that response returned for a request to a different, trusted origin when the method, path, and relevant headers match. This allows cross-origin information disclosure and persistent cache poisoning, including chains such as JWKS cache poisoning where a token signed with an attacker-held key is accepted as belonging to a trusted issuer. Applications that share `interceptors.cache()` or `interceptors.deduplicate()` state across origins are affected. An `Agent` is not affected, because its dispatch options include the request origin. This was introduced in undici 8.10.0 and affects 8.10.0 and 8.10.1. ## Patches Upgrade to undici v8.10.2. ## Workarounds Use a separate cache store and a separate interceptor instance for each origin, and do not share them across origins.

CVE-2026-85152 Affected Undici Versions

1 component(s)
Fixed Versions:
8.10.2
Product / Package Ecosystem Affected Versions Fixed Version
undici
npm
≥ 8.10.0
< 8.10.2
8.10.2

References

Frequently Asked Questions

What is CVE-2026-85152?
CVE-2026-85152 is a security vulnerability in Undici involving undici vulnerable to cross-origin cache poisoning via missing origin isolation in interceptors under CWE-346: Origin Validation Error.
Which Undici versions are affected?
Affected versions include releases prior to 8.10.2 across affected packages: undici.
What version fixes CVE-2026-85152?
Upgrading to 8.10.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is undici affected?
Yes, undici is affected in releases prior to 8.10.2. Upgrade your dependency to 8.10.2 or later.
What is the CVSS score of CVE-2026-85152?
CVE-2026-85152 has a CVSS v3.1 base score of 7.4 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-85152?
CVE-2026-85152 is classified under CWE-346: Origin Validation Error (The product does not properly verify that the source of data or communication is valid.).
How can I check npm dependencies for CVE-2026-85152?
Run the dependency tree command: 'npm ls undici'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vp8m-p9jh-q5pm",
  "modified" : "2026-09-29T18:15:13Z",
  "published" : "2026-09-29T18:15:13Z",
  "aliases" : [ "CVE-2026-85152" ],
  "summary" : "undici vulnerable to cross-origin cache poisoning via missing origin isolation in interceptors",
  "details" : "## Impact\n\nWhen `interceptors.cache()` or `interceptors.deduplicate()` is used with a dispatcher that does not carry a single authoritative origin, or when a request supplies its own `origin`, undici builds the cache and deduplication keys without the actual destination origin. If a cache store or interceptor instance is shared across more than one origin, otherwise-identical requests to different origins are keyed together.\n\nAn attacker who controls the response from one origin can then have that response returned for a request to a different, trusted origin when the method, path, and relevant headers match. This allows cross-origin information disclosure and persistent cache poisoning, including chains such as JWKS cache poisoning where a token signed with an attacker-held key is accepted as belonging to a trusted issuer.\n\nApplications that share `interceptors.cache()` or `interceptors.deduplicate()` state across origins are affected. An `Agent` is not affected, because its dispatch options include the request origin.\n\nThis was introduced in undici 8.10.0 and affects 8.10.0 and 8.10.1.\n\n## Patches\n\nUpgrade to undici v8.10.2.\n\n## Workarounds\n\nUse a separate cache store and a separate interceptor instance for each origin, and do not share them across origins.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "undici"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.10.0"
      }, {
        "fixed" : "8.10.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nodejs/undici/security/advisories/GHSA-vp8m-p9jh-q5pm"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-85152"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nodejs/undici/commit/caf6194d3dae989b731ed87ab85f182befe5eb80"
  }, {
    "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/v8.10.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-346" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-29T18:15:13Z",
    "nvd_published_at" : "2026-09-04T17:17:02Z"
  }
}