What is CVE-2026-18998?

CVE-2026-18998 is a medium-severity vulnerability in Cosmicstack-Labs Mercury-Agent, classified under Incorrect Privilege Assignment. CVSS score: 6.3/10. Published 2026-08-06.

How severe is CVE-2026-18998?

Medium severity. CVSS v3 base score is 6.3 out of 10.

Auth bypass in Cosmicstack-Labs Mercury-Agent

CVE-2026-18998

A vulnerability was determined in cosmicstack-labs mercury-agent up to 1.1.12. Impacted is the function SubAgent.run of the file src/core/sub-agent.ts of the component delegate_task Tool. Executing a manipulation can lead to improper authorization. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.

EPSS: 0.002 (11.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

Affected products

Cosmicstack-labs Mercury-agent — versions 1.1.0, 1.1.1, 1.1.2

Weakness classification (CWE)

References

cna@vuldb.com (technical-description, vdb-entry)
cna@vuldb.com (signature, permissions-required)
cna@vuldb.com (third-party-advisory)
cna@vuldb.com (third-party-advisory)
cna@vuldb.com (third-party-advisory)
cna@vuldb.com (issue-tracking, exploit)
cna@vuldb.com (product)

Frequently asked questions

What is CVE-2026-18998?: CVE-2026-18998 is a medium-severity vulnerability in Cosmicstack-Labs Mercury-Agent, classified under Incorrect Privilege Assignment. CVSS score: 6.3/10. Published 2026-08-06.
How severe is CVE-2026-18998?: Medium severity. CVSS v3 base score is 6.3 out of 10.