Monitor vulnerabilities like this one.
Sign up free to get alerted when software you use is affected.
6.9
Zebra Can Crash from Interrupted RPC Requests from Authorized Clients
GHSA-29x4-r6jv-ff4w
Summary
An authenticated client can crash a Zebra node by disconnecting during a request. This can happen if a client sends only part of a request and then drops the connection. To protect your Zebra nodes, make sure to update to a fixed version and consider disabling RPC access from the internet or limiting access to trusted clients.
What to do
- Update zebra-rpc to version 6.0.2.
- Update zebrad to version 4.3.1.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| rust | – | zebra-rpc |
>= 1.0.0-beta.45, < 6.0.2 Fix: upgrade to 6.0.2
|
| rust | – | zebrad |
>= 2.2.0, < 4.3.1 Fix: upgrade to 4.3.1
|
Original title
Zebra Vulnerable to Denial of Service via Interrupted JSON-RPC Requests from Authenticated Clients
Original description
A vulnerability in Zebra's JSON-RPC HTTP middleware allows an authenticated RPC client to cause a Zebra node to crash by disconnecting before the request body is fully received. The node treats the failure to read the HTTP request body as an unrecoverable error and aborts the process instead of returning an error response.
## Severity
**Moderate** - This is a Denial of Service (DoS) that requires a client capable of passing Zebra's cookie authentication, which is enabled by default.
## Affected Versions
- `zebrad`: versions from **2.2.0** up to (but not including) **4.3.1**
- `zebra-rpc`: versions from **1.0.0-beta.45** up to (but not including) **6.0.2**
## Description
Zebra's JSON-RPC HTTP middleware treated a failure to read the incoming HTTP request body as an unrecoverable error, aborting the process rather than returning an error response. A client that disconnected after sending only part of a request body, for example, by resetting the TCP connection mid-transfer, was sufficient to trigger the crash. The vulnerability could be exploited only by authenticated RPC clients. Nodes running the shipped defaults, with RPC bound to localhost and cookie authentication on, were not vulnerable.
## Impact
**Denial of Service**
* **Attack Vector:** Network, authenticated (requires a valid RPC cookie when cookie authentication is enabled).
* **Effect:** Immediate crash of the Zebra node.
* **Scope:** Any node whose RPC interface is reachable by a client with valid credentials, or any node with cookie authentication disabled and an exposed RPC interface.
## Fixed Versions
This issue is fixed in **Zebra 4.3.1** (crate `zebra-rpc` 6.0.2).
The fix propagates failures to read the HTTP request body as ordinary error responses, so Zebra now rejects truncated or interrupted requests rather than crashing.
## Mitigation
Users should upgrade to **Zebra 4.3.1** or later.
If an immediate upgrade is not possible, users should ensure their RPC port is not exposed to untrusted networks and that cookie authentication remains enabled (the default).
## References
* [Zebra 4.3.1 Release Announcement](https://zfnd.org/)
## Credits
Thanks to [shieldedonly](https://github.com/shieldedonly) who discovered this issue and reported it via our coordinated disclosure process.
## Severity
**Moderate** - This is a Denial of Service (DoS) that requires a client capable of passing Zebra's cookie authentication, which is enabled by default.
## Affected Versions
- `zebrad`: versions from **2.2.0** up to (but not including) **4.3.1**
- `zebra-rpc`: versions from **1.0.0-beta.45** up to (but not including) **6.0.2**
## Description
Zebra's JSON-RPC HTTP middleware treated a failure to read the incoming HTTP request body as an unrecoverable error, aborting the process rather than returning an error response. A client that disconnected after sending only part of a request body, for example, by resetting the TCP connection mid-transfer, was sufficient to trigger the crash. The vulnerability could be exploited only by authenticated RPC clients. Nodes running the shipped defaults, with RPC bound to localhost and cookie authentication on, were not vulnerable.
## Impact
**Denial of Service**
* **Attack Vector:** Network, authenticated (requires a valid RPC cookie when cookie authentication is enabled).
* **Effect:** Immediate crash of the Zebra node.
* **Scope:** Any node whose RPC interface is reachable by a client with valid credentials, or any node with cookie authentication disabled and an exposed RPC interface.
## Fixed Versions
This issue is fixed in **Zebra 4.3.1** (crate `zebra-rpc` 6.0.2).
The fix propagates failures to read the HTTP request body as ordinary error responses, so Zebra now rejects truncated or interrupted requests rather than crashing.
## Mitigation
Users should upgrade to **Zebra 4.3.1** or later.
If an immediate upgrade is not possible, users should ensure their RPC port is not exposed to untrusted networks and that cookie authentication remains enabled (the default).
## References
* [Zebra 4.3.1 Release Announcement](https://zfnd.org/)
## Credits
Thanks to [shieldedonly](https://github.com/shieldedonly) who discovered this issue and reported it via our coordinated disclosure process.
ghsa CVSS4.0
6.9
Vulnerability type
CWE-248
CWE-617
Published: 18 Apr 2026 · Updated: 18 Apr 2026 · First seen: 18 Apr 2026