CVE-2026-81515: CWE-755: Improper Handling of Exceptional Conditions in SteeltoeOSS security-advisories
## Summary Steeltoe's Eureka discovery client deserializes the registry response as a single unit. If any registered instance contains a field value that cannot be parsed (for example, an unrecognized `actionType`, a non-boolean value for `isCoordinatingDiscoveryServer`, or a non-numeric timestamp), deserialization of the entire registry fails. All Steeltoe Eureka clients connected to that registry then receive an empty or stale instance list until the malformed registration is removed. This is a related but distinct issue from [CVE-2026-50196](https://github.com/advisories/GHSA-j8ph-6fxj-g533), which addressed only the `DataCenterInfo.name` field. ## Impact Any principal that can register or update a service instance in the Eureka registry can trigger a service-discovery outage for all Steeltoe applications connected to the same registry. The outage persists until the offending registration is removed. ## Affected configuration * Application uses `EurekaDiscoveryClient` (any deployment, including self-hosted Eureka). * The registry contains at least one service instance with an unrecognized value in a field such as `actionType`, `status`, `isCoordinatingDiscoveryServer`, or timestamp fields. * Mixed-platform environments — for example, Java or Spring services co-existing in the same Eureka registry — are more likely to encounter this condition. ## Mitigations If an immediate upgrade is not possible: * Audit the Eureka registry for registrations containing non-standard field values, particularly those originating from non-.NET clients. * Restrict write access to the Eureka registration API to trusted services.
AI Analysis
Technical Summary
SteeltoeOSS, an open source library collection for cloud-native applications, has a vulnerability in versions >=4.0.0 <4.3.0 where the EurekaDiscoveryClient deserializes registry responses as a single unit. If the response contains an unrecognized actionType or status, a non-Boolean isCoordinatingDiscoveryServer, or a nonnumeric timestamp, the deserialization aborts the entire response. This improper handling of exceptional conditions affects the JsonInstanceInfoConverter, BoolStringJsonConverter, and LongStringJsonConverter parsing paths. An attacker with the ability to register or update an instance can cause all connected clients to receive empty or stale instance lists until the malformed registration is removed. This vulnerability is distinct from a prior DataCenterInfo.name parsing issue and is resolved in version 4.3.0.
Potential Impact
The vulnerability can cause a denial of service condition where all connected Steeltoe clients receive empty or stale instance lists, potentially disrupting service discovery and application functionality. There is no impact on confidentiality or integrity reported. The attack requires the ability to register or update an instance, which may limit the attack surface. No known exploits in the wild have been reported.
Mitigation Recommendations
Upgrade SteeltoeOSS to version 4.3.0 or later, where this issue is fixed. No other mitigations are indicated. Patch status is confirmed fixed in 4.3.0.
CVE-2026-81515: CWE-755: Improper Handling of Exceptional Conditions in SteeltoeOSS security-advisories
Description
## Summary Steeltoe's Eureka discovery client deserializes the registry response as a single unit. If any registered instance contains a field value that cannot be parsed (for example, an unrecognized `actionType`, a non-boolean value for `isCoordinatingDiscoveryServer`, or a non-numeric timestamp), deserialization of the entire registry fails. All Steeltoe Eureka clients connected to that registry then receive an empty or stale instance list until the malformed registration is removed. This is a related but distinct issue from [CVE-2026-50196](https://github.com/advisories/GHSA-j8ph-6fxj-g533), which addressed only the `DataCenterInfo.name` field. ## Impact Any principal that can register or update a service instance in the Eureka registry can trigger a service-discovery outage for all Steeltoe applications connected to the same registry. The outage persists until the offending registration is removed. ## Affected configuration * Application uses `EurekaDiscoveryClient` (any deployment, including self-hosted Eureka). * The registry contains at least one service instance with an unrecognized value in a field such as `actionType`, `status`, `isCoordinatingDiscoveryServer`, or timestamp fields. * Mixed-platform environments — for example, Java or Spring services co-existing in the same Eureka registry — are more likely to encounter this condition. ## Mitigations If an immediate upgrade is not possible: * Audit the Eureka registry for registrations containing non-standard field values, particularly those originating from non-.NET clients. * Restrict write access to the Eureka registration API to trusted services.
CVSS v3.1
Score 7.5high
Affected software
SteeltoeOSS
security-advisories
pkg:github/steeltoeoss/SteeltoeRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
SteeltoeOSS, an open source library collection for cloud-native applications, has a vulnerability in versions >=4.0.0 <4.3.0 where the EurekaDiscoveryClient deserializes registry responses as a single unit. If the response contains an unrecognized actionType or status, a non-Boolean isCoordinatingDiscoveryServer, or a nonnumeric timestamp, the deserialization aborts the entire response. This improper handling of exceptional conditions affects the JsonInstanceInfoConverter, BoolStringJsonConverter, and LongStringJsonConverter parsing paths. An attacker with the ability to register or update an instance can cause all connected clients to receive empty or stale instance lists until the malformed registration is removed. This vulnerability is distinct from a prior DataCenterInfo.name parsing issue and is resolved in version 4.3.0.
Potential Impact
The vulnerability can cause a denial of service condition where all connected Steeltoe clients receive empty or stale instance lists, potentially disrupting service discovery and application functionality. There is no impact on confidentiality or integrity reported. The attack requires the ability to register or update an instance, which may limit the attack surface. No known exploits in the wild have been reported.
Mitigation Recommendations
Upgrade SteeltoeOSS to version 4.3.0 or later, where this issue is fixed. No other mitigations are indicated. Patch status is confirmed fixed in 4.3.0.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-26T20:58:58.084Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aac0b8155bf5e2cf5942ee9
Added to database: 09/17/2026, 15:47:13 UTC
Last enriched: 09/17/2026, 16:01:49 UTC
Last updated: 09/18/2026, 01:15:15 UTC
Views: 9
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