CVE-2026-81516: CWE-755: Improper Handling of Exceptional Conditions in SteeltoeOSS security-advisories
## Summary Steeltoe's Consul discovery client parses the `secure` metadata field on each registered service instance using `bool.Parse`, which throws on any value other than `true` or `false`. A single service instance registered with a malformed `secure` value (for example `yes` or `1`) aborts construction of the entire instance list for that service, making the service undiscoverable. When `GetAllInstancesAsync` is used, one malformed instance in any service can abort enumeration across all services. This is the same "one malformed field aborts the whole batch" availability class as [CVE-2026-50196](https://github.com/advisories/GHSA-j8ph-6fxj-g533), but affecting the Consul discovery client. ## Impact Any principal that can register a service in the Consul catalog can trigger a service-discovery outage for all Steeltoe applications resolving that service. The outage affects all instances of the targeted service — not just the malformed one — and persists until the offending registration is removed. ## Affected configuration - Application uses `ConsulDiscoveryClient` (any deployment). - The Consul catalog contains at least one service instance with a `secure` metadata value that is not `true` or `false`. - Mixed-platform environments where non-.NET clients register services with non-standard metadata values are more likely to encounter this condition. ## Mitigations If an immediate upgrade is not possible: - Audit the Consul catalog for service registrations with non-standard `secure` metadata values. - Restrict write access to the Consul service registration API to trusted services.
AI Analysis
Technical Summary
CVE-2026-81516 describes an improper handling of exceptional conditions (CWE-755) in SteeltoeOSS's ConsulDiscoveryClient component between versions 4.0.0 and 4.3.0. When parsing secure metadata for ConsulServiceInstance objects, the code expects strict Boolean values. If a service registration supplies a secure value other than true or false, an exception is thrown that aborts the construction of the entire list of service instances. This causes the targeted service to become undiscoverable and disrupts service enumeration in GetAllInstancesAsync until the malformed registration is removed. The vulnerability results in a denial of service impacting availability. The issue is resolved in version 4.3.0.
Potential Impact
The vulnerability causes a denial of service by making a targeted service undiscoverable through the ConsulDiscoveryClient. This occurs because a malformed secure metadata value triggers an exception that aborts the enumeration of all service instances. Availability is impacted until the offending service registration is removed. There is no impact on confidentiality or integrity. 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. Until then, ensure that all Consul service registrations provide valid Boolean values for secure metadata to avoid triggering the exception. Removing malformed registrations will restore service discoverability. No other vendor advisories or patches are provided, so monitor for updates.
CVE-2026-81516: CWE-755: Improper Handling of Exceptional Conditions in SteeltoeOSS security-advisories
Description
## Summary Steeltoe's Consul discovery client parses the `secure` metadata field on each registered service instance using `bool.Parse`, which throws on any value other than `true` or `false`. A single service instance registered with a malformed `secure` value (for example `yes` or `1`) aborts construction of the entire instance list for that service, making the service undiscoverable. When `GetAllInstancesAsync` is used, one malformed instance in any service can abort enumeration across all services. This is the same "one malformed field aborts the whole batch" availability class as [CVE-2026-50196](https://github.com/advisories/GHSA-j8ph-6fxj-g533), but affecting the Consul discovery client. ## Impact Any principal that can register a service in the Consul catalog can trigger a service-discovery outage for all Steeltoe applications resolving that service. The outage affects all instances of the targeted service — not just the malformed one — and persists until the offending registration is removed. ## Affected configuration - Application uses `ConsulDiscoveryClient` (any deployment). - The Consul catalog contains at least one service instance with a `secure` metadata value that is not `true` or `false`. - Mixed-platform environments where non-.NET clients register services with non-standard metadata values are more likely to encounter this condition. ## Mitigations If an immediate upgrade is not possible: - Audit the Consul catalog for service registrations with non-standard `secure` metadata values. - Restrict write access to the Consul service registration API to trusted services.
CVSS v3.1
Score 7.5high
Affected software
SteeltoeOSS
security-advisories
pkg:nuget/SteeltoeOSS/security-advisoriesRun 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
CVE-2026-81516 describes an improper handling of exceptional conditions (CWE-755) in SteeltoeOSS's ConsulDiscoveryClient component between versions 4.0.0 and 4.3.0. When parsing secure metadata for ConsulServiceInstance objects, the code expects strict Boolean values. If a service registration supplies a secure value other than true or false, an exception is thrown that aborts the construction of the entire list of service instances. This causes the targeted service to become undiscoverable and disrupts service enumeration in GetAllInstancesAsync until the malformed registration is removed. The vulnerability results in a denial of service impacting availability. The issue is resolved in version 4.3.0.
Potential Impact
The vulnerability causes a denial of service by making a targeted service undiscoverable through the ConsulDiscoveryClient. This occurs because a malformed secure metadata value triggers an exception that aborts the enumeration of all service instances. Availability is impacted until the offending service registration is removed. There is no impact on confidentiality or integrity. 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. Until then, ensure that all Consul service registrations provide valid Boolean values for secure metadata to avoid triggering the exception. Removing malformed registrations will restore service discoverability. No other vendor advisories or patches are provided, so monitor for updates.
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: 6aac0b8155bf5e2cf5942eea
Added to database: 09/17/2026, 15:47:13 UTC
Last enriched: 09/17/2026, 16:01:44 UTC
Last updated: 09/18/2026, 01:15:15 UTC
Views: 10
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