CVE-2026-81515 Steeltoe.Discovery.Eureka: malformed enum/bool/timestamp field aborts entire registry fetch (DoS)
A malicious registration can cause Steeltoe Eureka clients to fail parsing, resulting in empty or stale service lists and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-81515?
CVE-2026-81515 is a high-severity denial of service vulnerability in SteeltoeOSS security-advisories, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. From 4.0.0 until 4.3.0, EurekaDiscoveryClient deserializes the registry response as one unit, and an unrecognized actionType or status, a non-Boolean isCoordinatingDiscoveryServer, or a nonnumeric timestamp can abort the entire response. A principal that can register or update an instance can cause all connected Steeltoe clients to receive an empty or stale instance list until the malformed registration is removed. The JsonInstanceInfoConverter, BoolStringJsonConverter, and LongStringJsonConverter parsing paths are affected. This issue is distinct from the earlier DataCenterInfo.name parsing vulnerability. This issue is fixed in version 4.3.0.
Weakness: CWE-755
Which versions are affected by CVE-2026-81515?
2 open source packages ship an affected version, including Steeltoe.Discovery.Eureka.
| Package | Affected | Fixed in |
|---|---|---|
Steeltoe.Discovery.Eureka NuGet | From 4.0.0 | 4.3.0 |
Steeltoe.Discovery.Eureka NuGet | From 4.0.0 | 4.3.0 |
How do I fix CVE-2026-81515?
Upgrade Steeltoe.Discovery.Eureka to 4.3.0 or later.
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-2026-81515 being exploited?
There is no known exploitation of CVE-2026-81515 in the wild and no public exploit code.
Sources
Also known as GHSA-hr73-3gpv-hh6q.