CVE-2026-7776
Published: 04 May 2026
Summary
CVE-2026-7776 is a high-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Hashicorp (inferred from references). Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 11.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
This control implements explicit throttling on session allocation, addressing the weakness of allocating resources without limits.
Plan testing exercises resource allocation limits and throttling during simulated failures, directly addressing weaknesses that allow unbounded resource use.
Contingency plan updates ensure recovery strategies address unbounded resource allocation, making it harder for attackers to exploit lack of throttling to cause prolonged outages.
Provides continuity when unbounded resource allocation at the primary site leads to exhaustion and downtime.
Alternate services allow operations to continue when primary allocation of resources lacks limits or throttling.
Explicit planning of security-related actions requires defining limits, windows, and resource allocations, making allocation without throttling far less likely.
Measures of performance include tracking allocation behavior and throttling effectiveness, reducing the window for resource exhaustion attacks.
Imposes an inactivity-based limit on network resource allocation, throttling the number of concurrently held connections.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The CVE describes a remotely exploitable flaw in a network listener (worker authentication) that allows unauthenticated attackers to trigger resource exhaustion and block legitimate connections, directly enabling Exploit Public-Facing Application (T1190) to achieve Application or System Exploitation denial-of-service (T1499.004).
NVD Description
Boundary Community Edition and Boundary Enterprise (“Boundary”) workers are vulnerable to a denial-of-service condition during node enrollment TLS handshakes. An attacker with network access to the worker authentication listener may open a connection and delay or withhold the client certificate…
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during the TLS handshake, causing worker connection handling to block. This may prevent legitimate worker connections from being accepted or routed. This vulnerability, CVE-2026-7776, is fixed in Boundary 0.21.3, 0.20.3, 0.19.5.
Deeper analysisAI
CVE-2026-7776 is a denial-of-service vulnerability affecting Boundary Community Edition and Boundary Enterprise workers from HashiCorp. The issue arises during node enrollment TLS handshakes on the worker authentication listener, where an attacker can open a connection and delay or withhold the client certificate. This causes the worker's connection handling to block, preventing legitimate worker connections from being accepted or routed. The vulnerability has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and is associated with CWE-770: Allocation of Resources Without Limits or Throttling.
An unauthenticated attacker with network access to the worker authentication listener can exploit this vulnerability remotely with low complexity and no user interaction required. By repeatedly opening connections and withholding the client certificate during the TLS handshake, the attacker can consume resources and block the worker from processing legitimate enrollments, leading to a denial-of-service condition that disrupts Boundary operations.
HashiCorp has addressed CVE-2026-7776 in Boundary releases 0.21.3, 0.20.3, and 0.19.5. Security practitioners should upgrade affected workers to one of these patched versions. Additional details are available in the HashiCorp security advisory at https://discuss.hashicorp.com/t/hcsec-2026-11-boundary-workers-vulnerable-to-denial-of-service-during-tls-handshake.
Details
- CWE(s)