CVE-2026-48034: @hulumi/policies Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-9vc9-4jv3-rf86
CWE-284
Published
Advisory Summary

CVE-2026-48034 is a HIGH remote code execution vulnerability (CWE-284: Improper Access Control) affecting @hulumi/policies libraries in the npm ecosystem. The issue involves @hulumi/policies has a hulumi-h5 bypass via decoy sibling resources targeting a different bucket. Remediation is available by upgrading affected packages to version 1.4.0.

CVE-2026-48034 at a Glance

CVE Identifier CVE-2026-48034
GHSA Identifier GHSA-9vc9-4jv3-rf86
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-284: Improper Access Control
Affected Product @hulumi/policies
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-48034

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

@hulumi/policies fixed: 1.4.0
npm install @hulumi/policies@1.4.0
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 @hulumi/policies

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-48034, inspect your project dependencies using npm:

npm ls @hulumi/policies

Analyze the terminal output to locate any version of @hulumi/policies in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.0), your application is affected.

Note: The npm ls @hulumi/policies 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-284: Improper Access Control, where the product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. In @hulumi/policies, 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

**Affected:** `@hulumi/policies` `< 1.4.0` — **Fixed in:** `1.4.0` — **Severity:** High — **CWE-284 (Improper Access Control)** #### Summary HULUMI-H1 forbids raw `aws:s3:Bucket` outside of Hulumi's `SecureBucket` component, with one exemption: a raw bucket that's a child of a `SecureBucket` is allowed because the component is responsible for the hardening. HULUMI-H5 is the defence-in-depth check that closes the H1 exemption — for any raw bucket claiming it, H5 verifies the five hardening sibling resources a real `SecureBucket` always emits (public-access block, SSE-KMS, ownership controls, versioning, TLS-only bucket policy) are actually present. The bug: H5 only checked the siblings' _types_. It never verified that those siblings actually applied to the bucket being exempted. A consumer (or compromised PR) could pair an unhardened raw bucket with five hardening sibling resources whose `bucket` property pointed at a _completely different_ bucket, and H5 would report no violation while the actual bucket shipped with zero hardened defaults. #### Impact Consumers using `HulumiHardeningPack` could ship a raw S3 bucket with no public-access block, no SSE-KMS, no ownership controls, no versioning, and no TLS-only bucket policy — while the policy pack reported the stack as compliant. #### Patches Upgrade to `@hulumi/policies@1.4.0`. The H5 sibling check now requires both (a) the sibling to share the same parent `SecureBucket` instance via the anchored URN helper from GHSA-2, AND (b) the sibling's `bucket` property — or, for the bucket policy, its `Resource` ARN list — to reference the exempted bucket explicitly. Five decoy siblings pointing at a different bucket no longer count. #### Workarounds None — the exemption itself is the mechanism, so the value-binding check is the only fix. #### Resources - [PR #178](https://github.com/kerberosmansour/hulumi/pull/178) (Cluster B); decoy-sibling regression cases in `packages/policies/tests/hulumi-hardening-pack.test.ts`. Supersedes [PR #175](https://github.com/kerberosmansour/hulumi/pull/175), which had addressed the value-binding half but on a stale base.

CVE-2026-48034 Affected @hulumi/policies Versions

1 component(s)
Fixed Versions:
1.4.0
Product / Package Ecosystem Affected Versions Fixed Version
@hulumi/policies
npm
< 1.4.0
1.4.0

References

Frequently Asked Questions

What is CVE-2026-48034?
CVE-2026-48034 is a security vulnerability in @hulumi/policies involving @hulumi/policies has a HULUMI-H5 bypass via decoy sibling resources targeting a different bucket under CWE-284: Improper Access Control.
Which @hulumi/policies versions are affected?
Affected versions include releases prior to 1.4.0 across affected packages: @hulumi/policies.
What version fixes CVE-2026-48034?
Upgrading to 1.4.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @hulumi/policies affected?
Yes, @hulumi/policies is affected in releases prior to 1.4.0. Upgrade your dependency to 1.4.0 or later.
What CWE is associated with CVE-2026-48034?
CVE-2026-48034 is classified under CWE-284: Improper Access Control (The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.).
How can I check npm dependencies for CVE-2026-48034?
Run the dependency tree command: 'npm ls @hulumi/policies'. 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-9vc9-4jv3-rf86",
  "modified" : "2026-06-10T13:38:25Z",
  "published" : "2026-06-10T13:38:15Z",
  "aliases" : [ "CVE-2026-48034" ],
  "summary" : "@hulumi/policies has a HULUMI-H5 bypass via decoy sibling resources targeting a different bucket",
  "details" : "**Affected:** `@hulumi/policies` `< 1.4.0` — **Fixed in:** `1.4.0` — **Severity:** High — **CWE-284 (Improper Access Control)**\n\n#### Summary\n\nHULUMI-H1 forbids raw `aws:s3:Bucket` outside of Hulumi's `SecureBucket` component, with one exemption: a raw bucket that's a child of a `SecureBucket` is allowed because the component is responsible for the hardening. HULUMI-H5 is the defence-in-depth check that closes the H1 exemption — for any raw bucket claiming it, H5 verifies the five hardening sibling resources a real `SecureBucket` always emits (public-access block, SSE-KMS, ownership controls, versioning, TLS-only bucket policy) are actually present.\n\nThe bug: H5 only checked the siblings' _types_. It never verified that those siblings actually applied to the bucket being exempted. A consumer (or compromised PR) could pair an unhardened raw bucket with five hardening sibling resources whose `bucket` property pointed at a _completely different_ bucket, and H5 would report no violation while the actual bucket shipped with zero hardened defaults.\n\n#### Impact\n\nConsumers using `HulumiHardeningPack` could ship a raw S3 bucket with no public-access block, no SSE-KMS, no ownership controls, no versioning, and no TLS-only bucket policy — while the policy pack reported the stack as compliant.\n\n#### Patches\n\nUpgrade to `@hulumi/policies@1.4.0`. The H5 sibling check now requires both (a) the sibling to share the same parent `SecureBucket` instance via the anchored URN helper from GHSA-2, AND (b) the sibling's `bucket` property — or, for the bucket policy, its `Resource` ARN list — to reference the exempted bucket explicitly. Five decoy siblings pointing at a different bucket no longer count.\n\n#### Workarounds\n\nNone — the exemption itself is the mechanism, so the value-binding check is the only fix.\n\n#### Resources\n\n- [PR #178](https://github.com/kerberosmansour/hulumi/pull/178) (Cluster B); decoy-sibling regression cases in `packages/policies/tests/hulumi-hardening-pack.test.ts`. Supersedes [PR #175](https://github.com/kerberosmansour/hulumi/pull/175), which had addressed the value-binding half but on a stale base.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@hulumi/policies"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/kerberosmansour/hulumi/security/advisories/GHSA-9vc9-4jv3-rf86"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kerberosmansour/hulumi/pull/175"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kerberosmansour/hulumi/pull/178"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kerberosmansour/hulumi"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-10T13:38:15Z",
    "nvd_published_at" : null
  }
}