# CVE-2026-7429: SSCMS v7.4.0 Reflected Cross-Site Scripting via STL Processing

> Attackers can inject malicious JavaScript via STL templates in SSCMS, leading to session hijacking and unauthorized user actions.

- **Severity:** Low 2.1 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 30 Apr 2026
- **Updated:** 28 Jul 2026
- **Also known as:** GHSA-h9g3-q89c-mhwg

## What is CVE-2026-7429?

CVE-2026-7429 is a low-severity cross-site scripting vulnerability in siteserver SSCMS, published on 30 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

SSCMS v7.4.0 contains a reflected cross-site scripting vulnerability in the STL processing endpoint that allows attackers to execute arbitrary JavaScript by crafting malicious STL template payloads that are decrypted and returned without proper sanitization. Attackers can exploit improper output encoding in the /api/stl/actions/dynamic endpoint to inject executable JavaScript into JSON responses, leading to session hijacking, phishing attacks, and unauthorized actions performed on behalf of users.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-7429?


## How do I fix CVE-2026-7429?

No fix has been published for CVE-2026-7429 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-7429 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-7429 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-7429 and fix it if it is affected.

What it is: CVE-2026-7429 is a low-severity cross-site scripting vulnerability in siteserver SSCMS, published on 30 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-7429 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-2026-7429/ (Markdown: https://insights.sbomify.com/CVE-2026-7429/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-7429
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-7429
- OSV: https://osv.dev/vulnerability/CVE-2026-7429

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-7429/
Summaries are generated and may contain mistakes; the official description above is the record.