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

published 2026-06-10 4 mo ago modified 2026-10-24 15 d ago also GHSA-9vc9-4jv3-rf86 , EUVD-2026-48734

cvss: 8.5; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits: 0; none known

Hulumi is an open-source toolkit that ships secure-by-default cloud and platform infrastructure components for Pulumi. Prior to version 1.4.0, there is a bypass via decoy sibling resources targeting a different bucket. This issue has been patched in version 1.4.0.

Patch / fix

fixed in 1 links 3

npm @hulumi/policies 1.4.0

github.com/kerberosmansour/hulumi#175 pull request
github.com/kerberosmansour/hulumi#178 pull request
github.com/kerberosmansour/hulumi/releases/tag/v1.4.0 release

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 3 mo ago (2026-07-24)

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.5	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
CNA	4.0	8.5	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem	package	affected	fixed in
npm	@hulumi/policies	<1.4.0	1.4.0

Affected products

kerberosmansour hulumi

Classification

Weakness

CWE-284 Improper Access Control

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary