CVE-2026-39911

HIGH 8.8

Hashgraph Guardian 3.5.0 Unsandboxed JavaScript Execution RCE

CVSS Score

8.8

EPSS Score

0.0%

EPSS Percentile

0th

Hashgraph Guardian through version 3.5.0 contains an unsandboxed JavaScript execution vulnerability in the Custom Logic policy block worker that allows authenticated Standard Registry users to execute arbitrary code by passing user-supplied JavaScript expressions directly to the Node.js Function() constructor without isolation. Attackers can import native Node.js modules to read arbitrary files from the container filesystem, access process environment variables containing sensitive credentials such as RSA private keys, JWT signing keys, and API tokens, and forge valid authentication tokens for any user including administrators.

CWE	CWE-668
Vendor	hashgraph
Product	guardian
Published	Apr 9, 2026
Last Updated	Apr 9, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

hashgraph / guardian

0 ≤ 3.5.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/hashgraph/guardian/pull/5929 vulncheck.com: https://www.vulncheck.com/advisories/hashgraph-guardian-unsandboxed-javascript-execution-rce

Credits

Christ Bouchuen