WeKnora Vulnerable to Tool Execution Hijacking via Ambigous Naming Convention In MCP client and Indirect Prompt Injection

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.4 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

EPSS

• CVE-2026-30856: 0.29% estimated exploitation activity in the next 30 days; percentile 21.68 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A vulnerability involving tool name collision and indirect prompt injection allows a malicious remote MCP server to hijack tool execution. By exploiting an ambiguous naming convention in the MCP client (mcp{service}{tool}), an attacker can register a malicious tool that overwrites a legitimate one (e.g., tavilyextract). This enables the attacker to redirect LLM execution flow, exfiltrate system prompts, context, and potentially execute other tools with the user's privileges. Details The vulnerability stems from two issues in the WeKnora client's MCP implementation: 1. Tool Name Collision (Ambiguous Sanitization): The client generates internal tool identifiers by sanitizing and joining the service name and tool name with underscores: mcp{service}{tool}. - Reference: internal/agent/tools/mcptool.go - The registry overwrites existing entries (internal/agent/tools/registry.go), so if a malicious service registers a tool that resolves to an existing name, it silently replaces the…

Published by the source

6 Mar 2026, 23:54 UTC

Last modified by the source

9 Mar 2026, 13:21 UTC

Source last checked

26 Oct 2026, 15:15 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-67q9-58vj-32qx

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# Patch Next advisory brief: CVE-2026-30856

Advisory: WeKnora Vulnerable to Tool Execution Hijacking via Ambigous Naming Convention In MCP client and Indirect Prompt Injection
IDs: CVE-2026-30856, GHSA-67q9-58vj-32qx
Record: https://patchnext.com/advisories/cve-2026-30856 (revision 1, source checked 26 Oct 2026, 15:15 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/Tencent/WeKnora 0.3.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/Tencent/WeKnora: affected <= 0.2.14; fixed in 0.3.0

## Suggested inspection (read-only)
- Go github.com/Tencent/WeKnora: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/Tencent/WeKnora.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-67q9-58vj-32qx (GitHub-reviewed advisory GHSA-67q9-58vj-32qx lists affected ranges: Go github.com/Tencent/WeKnora >=0 <=0.2.14)

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