Process hang via zero-input modular inverse
Published Mar 27, 2026 · Updated Mar 27, 2026
Denial of service in Digital Bazaar Forge before 1.4.0 allows remote attackers to hang a Node.js process through a zero modular-inverse input. The bnModInverse function in lib/jsbn.js enters its Extended Euclidean Algorithm without rejecting a zero target value, so its termination condition remains unreachable. Exploitation requires an application to pass attacker-controlled cryptographic data into modInverse; one such call blocks the Node.js event loop and leaves that process unresponsive.
Summary
What happened
Denial of service in Digital Bazaar Forge before 1.4.0 allows remote attackers to hang a Node.js process through a zero modular-inverse input. The bnModInverse function in lib/jsbn.js enters its Extended Euclidean Algorithm without rejecting a zero target value, so its termination condition remains unreachable. Exploitation requires an application to pass attacker-controlled cryptographic data into modInverse; one such call blocks the Node.js event loop and leaves that process unresponsive.
The record
- CVE
- CVE-2026-33891
- Published
- Mar 27, 2026
- Updated
- Mar 27, 2026
- Vendor
- Digital Bazaar
- Product
- Forge
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 27, 2026CVE publishedPublication date reported by the CVE source.
- Mar 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.4.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-5m6q-g25r-mvwx timeout proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo