CVE-2026-39911: Hashgraph Guardian through version 3.5.1, fixed in commit 45fbe2f, contains an unsandboxed JavaScript executio

Q: How do I fix CVE-2026-39911?

guardian: upgrade to newer than 3.5.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-39911 being exploited?

CVE-2026-39911 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-39911 affect?

CVE-2026-39911 affects guardian. Severity is high (CVSS 8.8). 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 cod

This month

HIGH 8.8UPGRADE

CVE-2026-39911 is a high-severity flaw (CVSS 8.8) affecting guardian. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 filesys

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-668
Published	2026-04-09
Last modified	2026-10-26

Publisher (CNA): VulnCheck · Vendor: hedera

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-09 18:17 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

hedera guardian UPGRADE

Affected: <= 3.5.0

Fixed in: newer than 3.5.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy guardian || rpm -q guardian || guardian --version

2. UPGRADE to newer than 3.5.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade guardian

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade guardian

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-39911?

guardian: upgrade to newer than 3.5.0. Exact commands for each OS are on this page.

Is CVE-2026-39911 being exploited?

CVE-2026-39911 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-39911 affect?

CVE-2026-39911 affects guardian. Severity is high (CVSS 8.8). 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 cod

How urgent is CVE-2026-39911?

Priority 42/100. High severity

Software pages

Node.js vulnerabilities

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References

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