Vulnerabilities in pkg:npm/@cedar-policy/authorization-for-expressjs

PACKAGE
Advisory Identifier: GHSA-g4w6-vmgf-xqvx
Advisory Summary

CVE-2026-49473 is a HIGH (CVSS 8.8) @cedar-policy/authorization-for-expressjs has an authorization bypass vulnerability (CWE-436: Interpretation Conflict) affecting @cedar policy/authorization for expressjs libraries in the npm ecosystem. The issue involves @cedar-policy/authorization-for-expressjs has an authorization bypass via query string manipulation. Remediation is available by upgrading affected packages to version 0.3.0.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:npm/@cedar-policy/authorization-for-expressjs

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:npm/@cedar-policy/authorization-for-expressjs. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-g4w6-vmgf-xqvx CVE-2026-49473 HIGH @cedar-policy/authorization-for-expressjs has an authorization bypass via query string manipulation

CVE-2026-49473 at a Glance

CVE Identifier CVE-2026-49473
GHSA Identifier GHSA-g4w6-vmgf-xqvx
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-436: Interpretation Conflict
Affected Product @cedar policy/authorization for expressjs
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 8.8

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

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

How to Fix CVE-2026-49473

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

@cedar-policy/authorization-for-expressjs fixed: 0.3.0
npm install @cedar-policy/authorization-for-expressjs@0.3.0
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 @cedar-policy/authorization-for-expressjs

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-49473, inspect your project dependencies using npm:

npm ls @cedar-policy/authorization-for-expressjs

Analyze the terminal output to locate any version of @cedar policy/authorization for expressjs in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.0), your application is affected.

Note: The npm ls @cedar-policy/authorization-for-expressjs 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-436: Interpretation Conflict, where product a handles inputs or steps differently than product b, which causes a to perform incorrect actions based on its perception of b's state. In @cedar policy/authorization for expressjs, 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

### Summary @cedar-policy/authorization-for-expressjs is an open-source Express.js middleware that integrates Cedar authorization into Express applications by mapping HTTP requests to Cedar actions and evaluating authorization policies before allowing requests to proceed. An issue exists where, under certain circumstances, the middleware matches incoming requests against Cedar action mappings using req.originalUrl, which includes the query string, while Express routes requests using only the path component. ### Impact The middleware uses req.originalUrl to match incoming requests against Cedar action mappings. In Express, req.originalUrl includes the query string, while route matching uses only the path. This creates a divergence between what Cedar authorizes and what Express executes. When an application defines separate actions for overlapping path prefixes with different authorization requirements (for example, GET /users for listing all users with admin-only access, and GET /users/{id} for retrieving a single user with any authenticated user access), an actor can append a query string to bypass the more restrictive policy. Sending GET /users/?x=1 causes the middleware to match against /users/{id} (with id parameter set to ?x=1) and evaluate the less restrictive action, while Express routes the request to the /users list handler. This allows inappropriate access to the more restrictive endpoint. ### Impacted versions <= 0.2.0 ### Patches This issue has been addressed in @cedar-policy/authorization-for-expressjs version 0.3. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. ### Workarounds Validate and sanitize incoming request paths before they reach the authorization middleware. Ensure that applications do not rely solely on the middleware for authorization when defining multiple actions on overlapping path prefixes with different permission levels. ### References If you have any questions or comments about this advisory, AWS asks that you contact AWS Security via the vulnerability reporting page or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue.

CVE-2026-49473 Affected @cedar policy/authorization for expressjs Versions

1 component(s)
Fixed Versions:
0.3.0
Product / Package Ecosystem Affected Versions Fixed Version
@cedar-policy/authorization-for-expressjs
npm
< 0.3.0
0.3.0

References

Frequently Asked Questions

What is CVE-2026-49473?
CVE-2026-49473 is a security vulnerability in @cedar policy/authorization for expressjs involving @cedar-policy/authorization-for-expressjs has an authorization bypass via query string manipulation under CWE-436: Interpretation Conflict.
Which @cedar policy/authorization for expressjs versions are affected?
Affected versions include releases prior to 0.3.0 across affected packages: @cedar-policy/authorization-for-expressjs.
What version fixes CVE-2026-49473?
Upgrading to 0.3.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @cedar-policy/authorization-for-expressjs affected?
Yes, @cedar-policy/authorization-for-expressjs is affected in releases prior to 0.3.0. Upgrade your dependency to 0.3.0 or later.
What is the CVSS score of CVE-2026-49473?
CVE-2026-49473 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-49473?
CVE-2026-49473 is classified under CWE-436: Interpretation Conflict (Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state.).
How can I check npm dependencies for CVE-2026-49473?
Run the dependency tree command: 'npm ls @cedar-policy/authorization-for-expressjs'. 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-g4w6-vmgf-xqvx",
  "modified" : "2026-06-30T18:09:13Z",
  "published" : "2026-06-30T18:09:13Z",
  "aliases" : [ "CVE-2026-49473" ],
  "summary" : "@cedar-policy/authorization-for-expressjs has an authorization bypass via query string manipulation",
  "details" : "### Summary\n@cedar-policy/authorization-for-expressjs is an open-source Express.js middleware that integrates Cedar authorization into Express applications by mapping HTTP requests to Cedar actions and evaluating authorization policies before allowing requests to proceed. An issue exists where, under certain circumstances, the middleware matches incoming requests against Cedar action mappings using req.originalUrl, which includes the query string, while Express routes requests using only the path component.\n\n### Impact\nThe middleware uses req.originalUrl to match incoming requests against Cedar action mappings. In Express, req.originalUrl includes the query string, while route matching uses only the path. This creates a divergence between what Cedar authorizes and what Express executes.\n\nWhen an application defines separate actions for overlapping path prefixes with different authorization requirements (for example, GET /users for listing all users with admin-only access, and GET /users/{id} for retrieving a single user with any authenticated user access), an actor can append a query string to bypass the more restrictive policy. Sending GET /users/?x=1 causes the middleware to match against /users/{id} (with id parameter set to ?x=1) and evaluate the less restrictive action, while Express routes the request to the /users list handler. This allows inappropriate access to the more restrictive endpoint.\n\n### Impacted versions\n<= 0.2.0\n\n### Patches\nThis issue has been addressed in @cedar-policy/authorization-for-expressjs version 0.3. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.\n\n### Workarounds\nValidate and sanitize incoming request paths before they reach the authorization middleware. Ensure that applications do not rely solely on the middleware for authorization when defining multiple actions on overlapping path prefixes with different permission levels.\n\n### References\nIf you have any questions or comments about this advisory, AWS asks that you contact AWS Security via the vulnerability reporting page or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@cedar-policy/authorization-for-expressjs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.2.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cedar-policy/authorization-for-expressjs/security/advisories/GHSA-g4w6-vmgf-xqvx"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cedar-policy/authorization-for-expressjs"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cedar-policy/authorization-for-expressjs/releases/tag/v0.3.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-436", "CWE-863" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-30T18:09:13Z",
    "nvd_published_at" : null
  }
}