CVE-2026-25923CWE-434CWE-502

Phar Deserialization leading to Arbitrary File Deletion in my little forum

High · published February 9, 2026

CVSS v4.0
8.7
EPSS
1%
Percentile
53.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.7 · HIGH
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
EPSS
0.00730 · 53.7th percentile
Weaknesses
CWE-434 · Unrestricted Upload of File with Dangerous Type; CWE-502 · Deserialization of Untrusted Data
Published
2026-02-09T21:56Z
EPSS history
Timeline
  • 09 FEB 21:56Z
    Phar Deserialization leading to Arbitrary File Deletion in my little forum
    cvelistv5