CVE-2025-1556 is a medium severity deserialization flaw in westboy CicadasCMS 1.0, in the Template Management feature at /system. NVD scores it 4.7. The attack needs a high privilege account. The record names no fix, so restrict the admin area and plan to replace the CMS.
What's affected
The record lists westboy CicadasCMS version 1.0. The affected area is the Template Management component, under the /system path. No fixed version is named in the record, and the researcher report we fetched does not announce a vendor patch. Treat the product as unfixed.
How to check if you're exposed
Find out if you run it. Search for the product in your deployment records and on your servers.
find / -maxdepth 6 -iname "*cicadascms*" 2>/dev/null
If you run it, check who holds administrator logins and whether the admin path can be reached from the internet.
The vector (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L) shows the attack needs a high privilege (administrator) account, which is why the score is medium. That limits who can try it, but compromised admin passwords are common, so do not rely on it.
What to do now
- Find every CicadasCMS installation and record its version.
- Restrict the admin area to a VPN or an allow list of addresses.
- Audit administrator accounts, remove unused ones and set strong unique passwords with a second factor where possible.
- Review template changes and recent admin activity for anything unexpected.
- Monitor the project for a fix, and plan a move to a maintained CMS if none appears.
Why it matters
The weakness is CWE-502, deserialization of untrusted data, with CWE-20, improper input validation, also listed. Deserialization turns stored or transmitted bytes back into live objects. If the data comes from someone untrusted, a crafted input can make the program build objects it never intended to.
The record rates the impact as low across the board and requires a high privilege account, so this is a lower priority than the unauthenticated bugs in this batch. Even so, an admin account that is compromised by phishing or reuse turns a medium issue into a stepping stone. It is not on the CISA KEV list.
Going further
Content management systems stay in service long after their developers move on. Put each one on a list with a named owner, and review the list yearly. A CMS with no visible maintenance and a public deserialization report is a replacement candidate, not a patching task.
If you must keep it, run it with least privilege: a separate system user, a read only file system for code, and a database account without administrative rights.
Quick check
Why is this only medium?
The attack needs a high privilege account, and the scored impact is low. That narrows the risk but does not remove it if admin credentials leak.
What is the lasting fix?
A vendor patch that validates or avoids untrusted deserialization. If none comes, replace the CMS or restrict the admin area tightly.
Sources
Last reviewed: 19 October 2026.
