Is CVE-2026-121618 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-121618 being exploited in the wild.

How severe is CVE-2026-121618?

Medium severity, with a CVSS score of 5.3, published 4 November 2026.

Is there a fix for CVE-2026-121618?

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-2026-121618 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-121618?

Check whether you run Linksys E5600 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.

CVE-2026-121618: Linksys E5600 unauthenticated information disclosure in factory QC page

CVE-2026-121618 · Severity: medium · CVSS 5.3 · Published 2026-11-04

The Linksys E5600 router's factory quality-control web page leaks sensitive device information including WiFi passwords and WPS PINs to unauthenticated remote users. An attacker can retrieve this data without logging in, enabling unauthorized wireless network access and targeted attacks against the device.

Technologies: Linksys E5600. Vendors: Linksys.

Quick answers

Is CVE-2026-121618 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-121618 being exploited in the wild.
How severe is CVE-2026-121618?: Medium severity, with a CVSS score of 5.3, published 4 November 2026.
Which products and versions are affected?: Linksys E5600 1.1.0.26.
Is there a fix for CVE-2026-121618?: 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-2026-121618 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-121618?: Check whether you run Linksys E5600 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

CWE-200 information disclosure: the /cgi-bin/fqc.cgi endpoint is exempt from authentication checks in the lighttpd configuration and outputs device identity data (serial number, MAC addresses, WiFi credentials, WPS PIN, firmware version) via shell variables. Remote unauthenticated attackers can trigger pre-authentication information disclosure with a simple HTTP GET request. A fix exists only for supported product versions; this device is end-of-life.

Affected products

Linksys E5600 1.1.0.26

Timeline

2026-11-04: disclosed

References

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