# CVE-2026-36615: Mercusys AC12G information disclosure in /agileconfigreset endpoint

Source: https://junglewise.ai/threats/cve-2026-36615-mercusys-ac12g-information-disclosure-in-agileconfigreset  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-03. Updated: 2026-06-03  
License: CC BY 4.0 with a link back

CVE-2026-36615 · Severity: info · CVSS 4.3 · Published 2026-06-03

An undocumented management endpoint in Mercusys AC12G routers allows unauthorized individuals on the same local network to view internal memory contents. This flaw could expose sensitive technical data about the router's operations or other users' web requests, which can be used to plan more advanced attacks. Because the product is at its end-of-life, no official security updates are expected.

Technologies: [Mercusys AC12G](https://junglewise.ai/threats/technologies/ac12g). Vendors: [Mercusys](https://junglewise.ai/threats/vendors/mercusys).

## Quick answers

**Is CVE-2026-36615 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36615 being exploited in the wild.

**How severe is CVE-2026-36615?** Informational severity, with a CVSS score of 4.3, published 3 June 2026.

**Which products and versions are affected?** Mercusys AC12G AC12G(EU)_V1_200909, AC12G(EU)_V1_210128.

**Is there a fix for CVE-2026-36615?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-36615 attacked?** It is attacked from the adjacent network, in a network appliance.

**Am I affected by CVE-2026-36615?** Check whether you run Mercusys AC12G at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The HTTP handler for the undocumented /agileconfigreset endpoint fails to properly manage internal buffers, leading to an information disclosure vulnerability. When an unauthenticated attacker sends a POST request to this endpoint, the router returns a malformed response containing 128 bytes of the internal HTTP header parse buffer. This buffer contains null-separated header names and values from the current request and potentially data from other clients' requests due to a shared buffer pool. The vulnerability is confirmed in firmware versions AC12G(EU)_V1_200909 and AC12G(EU)_V1_210128.

## Affected products

- Mercusys AC12G (EU) V1 AC12G(EU)_V1_200909, AC12G(EU)_V1_210128

## Timeline

- 2026-06-03: disclosed
- 2026-06-03: advisory

## References

- [https://github.com/Tymbark7372/MERCUSYS-AC12G/blob/master/advisories/CVE-2026-36615.md](https://github.com/Tymbark7372/MERCUSYS-AC12G/blob/master/advisories/CVE-2026-36615.md)

## Related threats

- [Mercusys AC12G hardcoded WiFi credentials in firmware](https://junglewise.ai/threats/cve-2026-36616-mercusys-ac12g-hardcoded-wifi-credentials-in-firmware)
- [Mercusys AC12G uninitialized buffer disclosure in UPnP](https://junglewise.ai/threats/cve-2026-36611-mercusys-ac12g-uninitialized-buffer-disclosure-in-upnp)
- [Mercusys AC12G V1 password recovery via static nonce and weak encoding](https://junglewise.ai/threats/cve-2026-36609-mercusys-ac12g-v1-password-recovery-via-static-nonce-and-weak)
- [Mercusys AC12G UPnP port forwarding to local admin interface](https://junglewise.ai/threats/cve-2026-36608-mercusys-ac12g-upnp-port-forwarding-to-local-admin-interface)
- [Mercusys AC12G hardcoded DES key in configuration backup](https://junglewise.ai/threats/cve-2026-36606-mercusys-ac12g-hardcoded-des-key-in-configuration-backup)