Unauthenticated worker enrollment denial via stalled TLS handshake
Published May 4, 2026 · Updated May 4, 2026
Denial of service in HashiCorp Boundary workers before 0.19.5, 0.20.3, or 0.21.3 allows remote attackers to block enrollment. The node-enrollment dependency performs the server-side mutual TLS handshake synchronously while accepting and classifying connections, so a client that withholds its certificate blocks the connection-handling path. Network access to the worker authentication listener is sufficient without successful authentication; later legitimate worker connections can be delayed or prevented.
Summary
What happened
Denial of service in HashiCorp Boundary workers before 0.19.5, 0.20.3, or 0.21.3 allows remote attackers to block enrollment. The node-enrollment dependency performs the server-side mutual TLS handshake synchronously while accepting and classifying connections, so a client that withholds its certificate blocks the connection-handling path. Network access to the worker authentication listener is sufficient without successful authentication; later legitimate worker connections can be delayed or prevented.
The record
- CVE
- CVE-2026-7776
- Published
- May 4, 2026
- Updated
- May 4, 2026
- Vendor
- HashiCorp
- Product
- Boundary Enterprise
- Classifications
- CWE-770, CAPEC-227, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 4, 2026CVE publishedPublication date reported by the CVE source.
- May 4, 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=0.9.0 <0.21.3 changes=[{"at":"0.19.5","status":"unaffected"},{"at":"0.20.3","status":"unaffected"},{"at":"0.21.3","status":"unaffected"}]
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
No public exploit references are available in this record.
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