Hashgraph Guardian through version 3.5.0 contains an unsandboxed JavaScript execution vulnerability in the Custom
Source GCVE Database
Not known to be exploited · CVSS 8.7 High.
Data as of 27 Oct 2026, 00:44 UTC
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| hashgraphguardian | Affected
| Fixed in– |
GitHubhashgraph/guardianpkg:github/hashgraph/guardianOther threats | Affected
| Fixed in– |
GitHubguardianpkg:github/guardianOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, restrict access to trusted users only and monitor for suspicious activity related to Custom Logic policy block usage.
Description
Hashgraph Guardian versions up to 3.5.0 have a vulnerability in the Custom Logic policy block worker that allows authenticated Standard Registry users to execute arbitrary JavaScript code without sandboxing. This flaw enables attackers to import native Node.js modules, read sensitive files, access environment variables containing credentials, and forge authentication tokens for any user, including administrators.
References
- nvd.nist.gov/vuln/detail/CVE-2026-39911 (opens in a new tab)
- github.com/hashgraph/guardian/pull/5929 (opens in a new tab)
- github.com/hashgraph/guardian/commit/45fbe2f7e0e8feee30105d42d66ed63fb6177ebe (opens in a new tab)
- vulncheck.com/advisories/hashgraph-guardian-unsandboxed-javascript-execution-rce (opens in a new tab)