How severe is CVE-2026-48034?

No CVSS score has been assigned to CVE-2026-48034 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-48034?

CVE-2026-48034 affects the following packages: @hulumi/policies (npm). Ecosystems affected: npm.

How do I fix CVE-2026-48034?

Update @hulumi/policies to 1.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48034 is resolved across your whole dependency graph.

How do I detect CVE-2026-48034 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @hulumi/policies, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-48034 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-48034 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-48034 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-48034?

CVE-2026-48034 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 38th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-48034?

CVE-2026-48034 is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-48034 published, and has it been updated?

CVE-2026-48034 was published on July 24, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-48034 — @hulumi/policies

Fix: kerberosmansour/hulumi#175

CVE-2026-48034 is a CWE-284 vulnerability in @hulumi/policies. A fix is available for @hulumi/policies — see the affected versions and patch details below.

HULUMI-H5 bypass via decoy sibling resources targeting a different bucket

Also known asGHSA-9vc9-4jv3-rf86

Published

Jul 24, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-48034.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs38th percentile — riskier than 38% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@hulumi/policiesnpm

40downloads / week

Description

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/[email protected]. 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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@hulumi/policies`	all versions	1.4.0`npm install @hulumi/policies@1.4.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @hulumi/policies, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @hulumi/policies to 1.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48034 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

**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,

O3 Security · Impact-Aware SCA

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