Quick answers
- Is CVE-2026-8739 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-8739 being exploited in the wild.
- How severe is CVE-2026-8739?
- Medium severity, with a CVSS score of 5.3, published 17 May 2026.
- Which products and versions are affected?
- Sanluan PublicCMS 5.202506.d.
- Is there a fix for CVE-2026-8739?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-8739 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-8739?
- Check whether you run Sanluan PublicCMS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A cryptographic design flaw exists in the SafeConfigComponent.getSignKey function of Sanluan PublicCMS 5.202506.d. The application uses a deterministic fallback value for the 'privatefile_key' when it is not explicitly configured. This key is derived from predictable inputs, including the site ID and a cluster identifier that is publicly exposed via the '/api/directive/tools/version' endpoint. An unauthenticated remote attacker can obtain these inputs, derive the signing key offline, and forge valid signatures for the '/file/private' endpoint. This allows for the unauthorized download of any private file if the file path is known. The vendor has reportedly not responded to disclosure attempts.
Affected products
- Sanluan PublicCMS 5.202506.d
Timeline
- 2026-05-17: advisory: CVE-2026-8739 published via NVD/VulDB
- 2026-05-17: disclosed: Exploit code and technical analysis made public