CVE-2026-102601: Flysystem is an open source file storage library for PHP. Prior to 3.35.3, the default WhitespacePathNormalizer in src/WhitespacePathNormalizer.php used by…

PriorityP417low3.5CVSS 3.1

AVNACLPRLUIRSUCNILAN

EPSS

0.34%

26.9th percentile

Flysystem is an open source file storage library for PHP. Prior to 3.35.3, the default WhitespacePathNormalizer in src/WhitespacePathNormalizer.php used by Filesystem across adapters calls preg_match with the u modifier and treats both false and 0 as falsy. A path containing malformed UTF-8 causes PCRE to return false, so paths that also contain control characters bypass CorruptedPathDetected::forPath() in normalizePath(). Filesystem::write() can store such names and Filesystem::listContents() can return the raw ANSI escape sequences, allowing hidden or spoofed terminal file listings when an administrator displays them. This issue is fixed in version 3.35.3.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
league	flysystem	>= 0 < 3.35.3	3.35.3
thephpleague	flysystem	< 3.35.3	3.35.3

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