Summary
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) 4.3.1zebra-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.
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
Credits
Thanks to shieldedonly who discovered this issue and reported it via our coordinated disclosure process.
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.
CVE-2026-41585 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (6.0.2, 4.3.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
zebra-rpc to 6.0.2 or later; zebrad to 4.3.1 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-41585? CVE-2026-41585 is a medium-severity security vulnerability in zebra-rpc (rust), affecting versions >= 1.0.0-beta.45, < 6.0.2. It is fixed in 6.0.2, 4.3.1.
- How severe is CVE-2026-41585? CVE-2026-41585 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2026-41585?
zebra-rpc(rust) (versions >= 1.0.0-beta.45, < 6.0.2)zebrad(rust) (versions >= 2.2.0, < 4.3.1)
- Is there a fix for CVE-2026-41585? Yes. CVE-2026-41585 is fixed in 6.0.2, 4.3.1. Upgrade to this version or later.
- Is CVE-2026-41585 exploitable, and should I be worried? Whether CVE-2026-41585 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-41585 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-41585?
- Upgrade
zebra-rpcto 6.0.2 or later - Upgrade
zebradto 4.3.1 or later
- Upgrade