Buffer overflow in Linksys E5600
CVE-2026-121616
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Linksys E5600 — versions 1.1.0.26
Weakness classification (CWE)
References
- vuldb.com/vuln/430464 (technical-description, vdb-entry)
- vuldb.com/vuln/430464/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-121616 (third-party-advisory)
- vuldb.com/submit/1023312 (third-party-advisory)
- github.com/Zimo-666/E5600-cves/tree/main/03-mesh-login-global-overflow (exploit)
- www.linksys.com/ (product)
Frequently asked questions
- What is CVE-2026-121616?
- CVE-2026-121616 is a medium-severity vulnerability in Linksys E5600, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.3/10. Published 2026-11-04.
- How severe is CVE-2026-121616?
- Medium severity. CVSS v3 base score is 5.3 out of 10.