Use of Uninitialized Variable in PHP - #VU151924
Published: September 24, 2026
Vulnerability identifier: #VU151924
CSH Severity: Low
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-457
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause inconsistent sanitization of 0xFF bytes.
The vulnerability exists due to use of uninitialized memory in the ext/filter FILTER_SANITIZE_ENCODED lookup table when processing input containing a 0xFF byte. A remote attacker can supply crafted input containing a 0xFF byte to cause inconsistent sanitization of 0xFF bytes.
All other input bytes are handled deterministically.
Affected software
PHP
Remediation
Install security update from vendor's website.
PHP - addressed in versions 8.2.34, 8.3.35, 8.4.25, 8.5.10