# CVE-2026-121618: Linksys E5600 Factory Quality Control fqc.cgi information disclosure

Status: published. Published: 2026-11-04. Updated: 2026-11-04.

A weakness has been identified in Linksys E5600 1.1.0.26. This affects an unknown part of the file /cgi-bin/fqc.cgi of the component Factory Quality Control. This manipulation causes information disclosure. Remote exploitation of the attack is possible. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way. This vulnerability only affects products that are no longer supported by the maintainer.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linksys / E5600: 1.1.0.26 (affected). Source: CNA: VulDB

## Severity and prioritization

- CVSS 4.0: 6.9 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P; source: CNA: VulDB

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:X/RC:C; source: CNA: VulDB

- CVSS 3.0: 5.3 (medium); CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:X/RC:C; source: CNA: VulDB

- CVSS 2.0: 5 (medium); AV:N/AC:L/Au:N/C:P/I:N/A:N/E:POC/RL:ND/RC:C; source: CNA: VulDB

- CVSS 4.0: 5.5 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: cna@vuldb.com

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N; source: NVD: cna@vuldb.com

- CVSS 2.0: 5 (medium); AV:N/AC:L/Au:N/C:P/I:N/A:N; source: NVD: cna@vuldb.com

- CISA KEV: No listing in collected sources

- EPSS: 0.75% as of 2026-11-04; percentile 55.16%

- SSVC: Not available

- Weaknesses: CWE-200, CWE-284

## Exploit evidence

- exploit: https://github.com/Zimo-666/E5600-cves/tree/main/05-fqc-info-disclosure (CNA: VulDB)

## References

- https://vuldb.com/vuln/430466 (CNA: VulDB; vdb-entry)

- https://vuldb.com/vuln/430466/cti (CNA: VulDB; signature, permissions-required)

- https://vuldb.com/cve/CVE-2026-121618 (CNA: VulDB; third-party-advisory)

- https://vuldb.com/submit/1023314 (CNA: VulDB; third-party-advisory)

- https://github.com/Zimo-666/E5600-cves/tree/main/05-fqc-info-disclosure (CNA: VulDB; exploit)

- https://www.linksys.com/ (CNA: VulDB; product)

- https://github.com/Zimo-666/E5600-cves/tree/main/05-fqc-info-disclosure (cna@vuldb.com)

- https://vuldb.com/cve/CVE-2026-121618 (cna@vuldb.com)

- https://vuldb.com/submit/1023314 (cna@vuldb.com)

- https://vuldb.com/vuln/430466 (cna@vuldb.com)

- https://vuldb.com/vuln/430466/cti (cna@vuldb.com)

- https://www.linksys.com/ (cna@vuldb.com)

## Provenance

- CNA: VulDB: https://www.cve.org/CVERecord?id=CVE-2026-121618; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121618; retrieved 2026-11-04; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-121618; retrieved 2026-11-05; source updated Not reported

Revision: 7d522999b0e8e45bc01022c7005d8af126d8253983e9f91802483a439b57e565

Canonical: https://y2.dev/cve/CVE-2026-121618

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