PT-2026-48476 · Npm · @Hulumi/Policies

Published 2026-06-10 · Updated 2026-06-10 · CVE-2026-48034

OSV

CVSS v4.0

8.5

High

Base vector

AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:L

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 (Cluster B); decoy-sibling regression cases in packages/policies/tests/hulumi-hardening-pack.test.ts. Supersedes PR #175, which had addressed the value-binding half but on a stale base.

Fix

Improper Access Control

Weakness Enumeration

CWE-284

Related Identifiers

CVE-2026-48034

GHSA-9VC9-4JV3-RF86

Affected Products

@Hulumi/Policies

References · 5

• https://osv.dev/vulnerability/GHSA-9vc9-4jv3-rf86 · Vendor Advisory
• https://github.com/kerberosmansour/hulumi · Note
• https://github.com/kerberosmansour/hulumi/pull/175 · Note
• https://github.com/kerberosmansour/hulumi/security/advisories/GHSA-9vc9-4jv3-rf86 · Note
• https://github.com/kerberosmansour/hulumi/pull/178 · Note