Improper Privilege Assignment in cosmicstack-labs mercury-agent
CVE-2026-18996

5.3MEDIUM

Key Information:

Vendor

Cosmicstack-labs

Status
Mercury-agent
Vendor
CVE Published:
6 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-18996?

A security weakness has been identified in cosmicstack-labs mercury-agent, specifically within the PermissionManager.checkShellCommand function located in the src/capabilities/permissions.ts file. This issue arises from incorrect privilege assignment that could be exploited remotely. The vulnerability allows an attacker to manipulate permissions improperly, potentially enabling unauthorized actions. Although the project team was alerted to this issue via an issue report, no response has been recorded to date. Users are advised to review their configurations and update to avoid potential exposure.

Affected Version(s)

mercury-agent 1.1.0

mercury-agent 1.1.1

mercury-agent 1.1.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-18996 - Proof of Concept

References

https://vuldb.com/vuln/386379
vdb-entrytechnical-description
https://vuldb.com/vuln/386379/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-18996
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

ChenMarry (VulDB User)
VulDB CNA Team
.