CVE-2026-7776 — boundary
HIGHCVE-2026-7776 is a high-severity (CVSS 7.5) CWE-770 vulnerability in github.com/hashicorp/boundary. A fix is available for github.com/hashicorp/boundary — see the affected versions and patch details below.
Boundary Workers Vulnerable to Denial of Service During TLS Handshake
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-7776.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/hashicorp/boundary🐹github.com/hashicorp/boundary🐹github.com/hashicorp/boundaryReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/hashicorp/boundary | all versions | 0.19.5go get github.com/hashicorp/boundary@v0.19.5 |
| 🐹Go | github.com/hashicorp/boundary | ≥ 0.20.0&&< 0.20.3 | 0.20.3go get github.com/hashicorp/boundary@v0.20.3 |
| 🐹Go | github.com/hashicorp/boundary | ≥ 0.21.0&&< 0.21.3 | 0.21.3go get github.com/hashicorp/boundary@v0.21.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/hashicorp/boundary, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/hashicorp/boundary to 0.19.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-7776 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2026-7776 in your dependencies?
Find it across Go, including transitive dependencies.