What is CVE-2026-111658?

CVE-2026-111658 is a low-severity vulnerability in Siteserver Sscms, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 3.8/10. Published 2026-10-16.

How severe is CVE-2026-111658?

Low severity. CVSS v3 base score is 3.8 out of 10.

Auth bypass in Siteserver Sscms

CVE-2026-111658

SiteServer SSCMS through 7.4.0 contains an authorization bypass vulnerability in ChannelsController that allows site-scoped administrators to access other sites' channels by supplying foreign channel IDs. Attackers with Channels permission on one site can read and overwrite another site's channel names, file paths, templates, link URLs, and custom fields, breaking multi-site isolation.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published 2026-10-16 · last modified 2026-10-16.

CVSS v3 metric

CVSS v3 base score 3.8 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/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

Siteserver Sscms

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

hackmd.io/@hieuPenguinnn/sscms-cross-site-channel-idor (third-party-advisory)
github.com/siteserver/cms/blob/sscms-v7.2.1/src/SSCMS.Web/Controllers/Admin/Cms… (technical-description)
github.com/siteserver/cms/blob/sscms-v7.2.1/src/SSCMS.Web/Controllers/Admin/Cms… (technical-description)
www.vulncheck.com/advisories/siteserver-sscms-through-7.4.0-cross-site-authoriz… (third-party-advisory)

Frequently asked questions

What is CVE-2026-111658?: CVE-2026-111658 is a low-severity vulnerability in Siteserver Sscms, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 3.8/10. Published 2026-10-16.
How severe is CVE-2026-111658?: Low severity. CVSS v3 base score is 3.8 out of 10.