# CVE-2026-121616: Linksys E5600 JSON Request mesh_login.cgi strcpy out-of-bounds write

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

A vulnerability was identified in Linksys E5600 1.1.0.26. Affected by this vulnerability is the function strcpy of the file /cgi-bin/mesh_login.cgi of the component JSON Request Parser. The manipulation of the argument username/password/token/source/cn/action leads to out-of-bounds write. The attack may be initiated remotely. The exploit is publicly available and might be used. 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:N/VI:L/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:N/I:L/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:N/I:L/A:N/E:P/RL:X/RC:C; source: CNA: VulDB

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

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-787, CWE-119

## Exploit evidence

- exploit: https://github.com/Zimo-666/E5600-cves/tree/main/03-mesh-login-global-overflow (CNA: VulDB)

## References

- https://vuldb.com/vuln/430464 (CNA: VulDB; vdb-entry, technical-description)

- https://vuldb.com/vuln/430464/cti (CNA: VulDB; signature, permissions-required)

- https://vuldb.com/cve/CVE-2026-121616 (CNA: VulDB; third-party-advisory)

- https://vuldb.com/submit/1023312 (CNA: VulDB; third-party-advisory)

- https://github.com/Zimo-666/E5600-cves/tree/main/03-mesh-login-global-overflow (CNA: VulDB; exploit)

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

## Provenance

- CNA: VulDB: https://www.cve.org/CVERecord?id=CVE-2026-121616; retrieved 2026-11-04; source updated 2026-11-04

Revision: 15ba6bbd55cea9519f308854fad307416793d3ded3ea451f8388ced682d555b8

Canonical: https://y2.dev/cve/CVE-2026-121616

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