Improper Authorization Vulnerability in Cosmicstack-Labs Mercury-Agent Software
CVE-2026-18998

5.3MEDIUM

Key Information:

Vendor

Cosmicstack-labs

Status
Mercury-agent
Vendor
CVE Published:
6 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-18998?

A vulnerability exists in the Cosmicstack-Labs Mercury-Agent software that allows for improper authorization within the function SubAgent.run found in the delegate_task Tool. This issue affects versions up to 1.1.12 and can be exploited remotely. Details regarding this vulnerability were made publicly available after it was reported to the project, although there has been no formal acknowledgment from the developers. Users are encouraged to assess their exposure and take appropriate measures to mitigate potential risks.

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-2026-18998 - Proof of Concept

References

https://vuldb.com/vuln/386381
vdb-entrytechnical-description
https://vuldb.com/vuln/386381/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-18998
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
.