Skip to main content

CVE-2026-81516: CWE-755: Improper Handling of Exceptional Conditions in SteeltoeOSS security-advisories

0
High
Published: 09/17/2026 (09/17/2026, 20:30:54 UTC)
Source: CVE Database V5
Vendor/Project: SteeltoeOSS
Product: 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

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected software

SteeltoeOSS

security-advisories

Affected versions
>=4.0.0 <4.3.0
SteeltoeOSS/security-advisories
pkg:nuget/SteeltoeOSS/security-advisories
Affected versions
>=4.0.0 <4.3.0

Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/17/2026, 16:01:44 UTC

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.

Pro Console: star threats, build custom feeds, automate alerts via Slack, email & webhooks.Upgrade to Pro

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

Community Reviews

0 reviews

Crowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.

Sort by
Loading community insights…

Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.

Actions

PRO

Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.

Please log in to the Console to use AI analysis features.

Need more coverage?

Upgrade to Pro Console for AI refresh and higher limits.

For incident response and remediation, OffSeq services can help resolve threats faster.

Latest Threats

Breach by OffSeqOFFSEQFRIENDS — 25% OFF

Check if your credentials are on the dark web

Instant breach scanning across billions of leaked records. Free tier available.

Scan now
OffSeq TrainingCredly Certified

Lead Pen Test Professional

Technical5-day eLearningPECB Accredited
View courses