# CVE-2026-111658: SiteServer SSCMS through 7.4.0 Cross-Site Authorization Bypass via Channels API

> Site-scoped administrators can bypass isolation to read and modify other sites' channel data in SSCMS.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** GHSA-f64v-vg62-99f4

## What is CVE-2026-111658?

CVE-2026-111658 is a medium-severity missing authorization vulnerability in SiteServer SSCMS, published on 16 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

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.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-111658?


## How do I fix CVE-2026-111658?

No fix has been published for CVE-2026-111658 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-111658 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111658 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111658 and fix it if it is affected.

What it is: CVE-2026-111658 is a medium-severity missing authorization vulnerability in SiteServer SSCMS, published on 16 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111658 exists.

Affected product: SiteServer SSCMS. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-111658/ (Markdown: https://insights.sbomify.com/CVE-2026-111658/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111658
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111658
- OSV: https://osv.dev/vulnerability/CVE-2026-111658

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111658/
Summaries are generated and may contain mistakes; the official description above is the record.