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Resource Allocation Without LimitsWeakness · CWE-770

CVE-2026-7776

HIGH · 7.5 CVSS v3.1 Published 2026-05-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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 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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Boundary workers are vulnerable to a DoS condition where an attacker with network access to the worker authentication listener can block worker connections by opening connections and delaying or withholding the client certificate during TLS handshakes. This causes worker connection handling to block, preventing legitimate worker connections from being accepted or routed.

MitigationUpgrade Boundary to version 0.21.3, 0.20.3, or 0.19.5 to patch the TLS handshake vulnerability. Consider network segmentation to limit access to worker authentication listeners.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Boundary version
    Run `boundary --version` or check the version from the binary/package that is deployed
    Affected if Version is 0.21.0-0.21.2, 0.20.0-0.20.2, 0.19.0-0.19.4, or any earlier version (patches are in 0.21.3, 0.20.3, 0.19.5)
  2. Identify if worker authentication listeners are configured
    Review Boundary controller configuration files (typically HCL or environment variables) for `listener` blocks with `purpose` set to `worker` or worker-related authentication endpoints
    Affected if Worker authentication listeners are defined and exposed on accessible network interfaces
  3. Verify network exposure of worker authentication endpoints
    Check firewall rules, network ACLs, or cloud security groups that allow inbound access to the worker authentication listener port from untrusted networks
    Affected if The worker authentication listener port is reachable from networks where untrusted actors exist (e.g., public internet, shared networks)
  4. Confirm active worker registrations
    Run `boundary workers list -scope=<controller-scope-id>` or check controller logs for connected workers
    Affected if Workers are actively registering to the controller via the vulnerable TLS handshake path

If running a Boundary version prior to 0.21.3, 0.20.3, or 0.19.5 AND the worker authentication listener is network-accessible, the environment is vulnerable to this DoS condition.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Boundary to version 0.21.3, 0.20.3, or 0.19.5 to patch the TLS handshake vulnerability. Consider network segmentation to limit access to worker authentication listeners.

Recommended fix High confidence

Boundary 0.21.3 (recommended latest) or 0.20.3 or 0.19.5

  1. 1. Back up your current Boundary installation and configuration
  2. 2. Review the HashiCorp Boundary upgrade documentation for your current version
  3. 3. Upgrade Boundary to version 0.21.3, 0.20.3, or 0.19.5 (preferably the latest stable release among these)
  4. 4. After upgrade, verify that worker connections are being accepted properly
  5. 5. Monitor worker authentication listener to confirm the DoS condition is resolved

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-7776 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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