CVE-2026-25923 PUBLISHED

Phar Deserialization leading to Arbitrary File Deletion in my little forum

Assigner: GitHub_M
Reserved: 09.02.2026 Published: 09.02.2026 Updated: 09.02.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

Product Status

Vendor My-Little-Forum
Product mylittleforum
Versions
  • Version < 20260208.1 is affected

References

Problem Types

  • CWE-434: Unrestricted Upload of File with Dangerous Type CWE
  • CWE-502: Deserialization of Untrusted Data CWE