Is CVE-2026-121933 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-121933 being exploited in the wild.

How severe is CVE-2026-121933?

Critical severity, with a CVSS score of 10, published 4 November 2026.

Is there a fix for CVE-2026-121933?

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-2026-121933 attacked?

It is attacked over the network or from the adjacent network, in a network appliance.

Am I affected by CVE-2026-121933?

Check whether you run Linksys E5350 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-2026-121933: Linksys E5350 authentication bypass in Setup Wizard

CVE-2026-121933 · Severity: critical · CVSS 10 · Published 2026-11-04

The Linksys E5350 wireless router's setup wizard allows an attacker or user to set an empty administrator password, which then bypasses all authentication checks permanently. An attacker on the local network can remotely access the entire management interface—including features that execute system commands—without any credentials, gaining full control of the router.

Vendors: Linksys.

Quick answers

Is CVE-2026-121933 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-121933 being exploited in the wild.
How severe is CVE-2026-121933?: Critical severity, with a CVSS score of 10, published 4 November 2026.
Which products and versions are affected?: Linksys E5350 1.0.00.037.
Is there a fix for CVE-2026-121933?: 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-2026-121933 attacked?: It is attacked over the network or from the adjacent network, in a network appliance.
Am I affected by CVE-2026-121933?: Check whether you run Linksys E5350 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 vulnerability is an improper authentication flaw (CWE-306, CWE-258) in the setup wizard's save_settings handler (/wizard/apply.cgi), which accepts an empty router_pwd parameter without validation and persists it to NVRAM. The httpd authentication core then treats an empty stored password as a successful authentication when wizard_finish=1 and close_session=1, bypassing credential checks for all protected endpoints. An attacker can reach the unauthenticated setup wizard during factory state or after completion to trigger command injection on protected Diagnostics endpoints.

Affected products

Linksys E5350 1.0.00.037

Timeline

2026-11-04: disclosed: Public disclosure via NVD and GitHub
2026-11-04: exploited: Exploit published and available

References

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