CVE-2026-39911 Hashgraph Guardian 3.5.1 Unsandboxed JavaScript Execution RCE
Authenticated users can execute arbitrary code via unsandboxed JavaScript, leading to credential theft and administrative token forgery.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-39911?
CVE-2026-39911 is a high-severity code injection vulnerability in hashgraph guardian, published on 9 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-668
Which versions are affected by CVE-2026-39911?
It affects 1 product.
Products include Hedera Guardian.
How do I fix CVE-2026-39911?
No fix has been published for CVE-2026-39911 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-39911 being exploited?
There is no known exploitation of CVE-2026-39911 in the wild and no public exploit code.
Other vulnerabilities in hashgraph guardian
Sources
Also known as GHSA-wf7f-q2xr-hrmh.