Vulnerability · Published Apr 9, 2026 · Assigned by VulnCheck

CVE-2026-39911Hashgraph Guardian 3.5.1 Unsandboxed JavaScript Execution RCE

High 8.8

In plain English

A high-severity security flaw in guardian from hashgraph. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 46% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.6%top 53.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
hashgraph	guardian	0 – through 3.5.1

Weakness: CWE-668 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/hashgraph/guardian/pull/5929 issue-tracking
https://github.com/hashgraph/guardian/commit/45fbe2f7e0e8feee30105d42d66ed63fb6177ebe patch
https://www.vulncheck.com/advisories/hashgraph-guardian-unsandboxed-javascript-execution-rce third-party-advisory