Vulnerability in Hashgraph Guardian
CVE-2026-39911
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.008 (54.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.008 · change: +0.002
Affected products
- Hashgraph Guardian — versions 0, 45fbe2f7e0e8feee30105d42d66ed63fb6177ebe
- Hedera Guardian
Weakness classification (CWE)
References
- github.com/hashgraph/guardian/pull/5929 (issue-tracking, Issue Tracking, mitigation)
- github.com/hashgraph/guardian/commit/45fbe2f7e0e8feee30105d42d66ed63fb6177ebe (patch)
- www.vulncheck.com/advisories/hashgraph-guardian-unsandboxed-javascript-executio… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-39911?
- CVE-2026-39911 is a high-severity vulnerability in Hashgraph Guardian, classified under Exposure of Resource to Wrong Sphere. CVSS score: 8.8/10. Published 2026-04-09.
- How severe is CVE-2026-39911?
- High severity. CVSS v3 base score is 8.8 out of 10.