CVE-2026-7776 Boundary Workers Vulnerable to Denial of Service During TLS Handshake
Attackers can cause denial of service in Boundary workers by delaying TLS handshakes, blocking legitimate connections.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-7776?
CVE-2026-7776 is a high-severity denial of service vulnerability in HashiCorp Boundary, published on 4 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-770
Which versions are affected by CVE-2026-7776?
7 open source packages ship an affected version, including github.com/hashicorp/boundary.
| Package | Affected | Fixed in |
|---|---|---|
github.com/hashicorp/boundary Go | All versions | 0.19.5, 0.20.3, 0.21.3 |
github.com/hashicorp/boundary Go | All versions | 0.19.5 |
github.com/hashicorp/boundary Go | All versions | 0.19.5 |
github.com/hashicorp/boundary Go | From 0.20.0 | 0.20.3 |
github.com/hashicorp/boundary Go | From 0.20.0 | 0.20.3 |
github.com/hashicorp/boundary Go | From 0.21.0 | 0.21.3 |
1 more packages
github.com/hashicorp/boundary Go | From 0.21.0 | 0.21.3 |
How do I fix CVE-2026-7776?
Upgrade github.com/hashicorp/boundary to a fixed version for your release line: 0.19.5, 0.20.3 or 0.21.3.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-7776 being exploited?
There is no known exploitation of CVE-2026-7776 in the wild and no public exploit code.
Sources
Also known as GHSA-7x9r-wcgg-w86f, GO-2026-5237.