CVE-2026-39911

Hashgraph Guardian 3.5.1 Unsandboxed JavaScript Execution RCE

HIGH
8.8
CVSS Score
Published: April 9, 2026 at 05:57 PM UTC
Updated: October 26, 2026 at 09:10 PM UTC
2 products affected across 2 vendorsGuardianGuardian

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Severity
HIGH8.8
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 3.5.0
v ≤ 3.5.1
Vendor states this is fixed in 45fbe2f7e0e8feee30105d42d66ed63fb6177ebe (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-668

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