CVE-2026-39911

High

Description

Hashgraph Guardian through version 3.5.1, fixed in commit 45fbe2f, 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.

SeverityHigh
CVSS8.8
Exploit probability—
ProductHedera Guardian
PublishedApr 9, 2026
First seenApr 9, 2026
Weakness typeCWE-668CWE-668

How to fix

Affected products

ProductAffected versionsFixed in
hedera guardianv ≤ 3.5.0—

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