# CVE-2026-8739: Sanluan PublicCMS SafeConfigComponent.java getSignKey hard-coded key

> Remote attackers can exploit a hard-coded cryptographic key in PublicCMS to bypass security mechanisms, as the vendor has not provided a fix.

- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 May 2026
- **Updated:** 18 May 2026
- **Also known as:** GHSA-2352-54f8-q7h5

## What is CVE-2026-8739?

CVE-2026-8739 is a medium-severity vulnerability in Sanluan PublicCMS, published on 17 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was detected in Sanluan PublicCMS 5.202506.d. The affected element is the function getSignKey of the file publiccms-core/src/main/java/com/publiccms/logic/component/config/SafeConfigComponent.java. The manipulation of the argument privatefile_key results in use of hard-coded cryptographic key
 . The attack can be executed remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-321 (Use of Hard-coded Cryptographic Key), CWE-320

## Which versions are affected by CVE-2026-8739?


## How do I fix CVE-2026-8739?

No fix has been published for CVE-2026-8739 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8739 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8739 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8739 and fix it if it is affected.

What it is: CVE-2026-8739 is a medium-severity vulnerability in Sanluan PublicCMS, published on 17 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8739 exists.

Affected product: Sanluan PublicCMS. 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-2026-8739/ (Markdown: https://insights.sbomify.com/CVE-2026-8739/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8739
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8739
- OSV: https://osv.dev/vulnerability/CVE-2026-8739

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8739/
Summaries are generated and may contain mistakes; the official description above is the record.