CVE-2026-25923 Phar Deserialization leading to Arbitrary File Deletion in my little forum
Attackers can delete arbitrary files by uploading a malicious Phar polyglot image and triggering deserialization via BBCode processing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-25923?
CVE-2026-25923 is a high-severity unsafe deserialization vulnerability in My-Little-Forum mylittleforum, published on 9 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
my little forum is a PHP and MySQL based internet forum that displays the messages in classical threaded view. Prior to 20260208.1, the application fails to filter the phar:// protocol in URL validation, allowing attackers to upload a malicious Phar Polyglot file (disguised as JPEG) via the image upload feature, trigger Phar deserialization through BBCode [img] tag processing, and exploit Smarty 4.1.0 POP chain to achieve arbitrary file deletion. This vulnerability is fixed in 20260208.1.
Which versions are affected by CVE-2026-25923?
It affects 1 product.
Products include Mylittleforum My Little Forum.
How do I fix CVE-2026-25923?
No fix has been published for CVE-2026-25923 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-25923 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25923 exists.
Other vulnerabilities in My-Little-Forum mylittleforum
Sources
Also known as GHSA-wr9p-3c3g-78fw.