CVE-2026-18998 cosmicstack-labs mercury-agent delegate_task Tool sub-agent.ts SubAgent.run improper authorization
Remote attackers can bypass authorization checks in the delegate_task tool to execute unauthorized sub-agent operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-18998?
CVE-2026-18998 is a medium-severity missing authorization vulnerability in cosmicstack-labs mercury-agent, published on 6 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-18998?
How do I fix CVE-2026-18998?
No fix has been published for CVE-2026-18998 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-18998 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18998 exists.
Sources
Also known as GHSA-7hmv-r6w5-pr73.