CVE-2026-102601 — Flysystem: WhitespacePathNormalizer's control-character (CorruptedPathDetected) check is bypassed by malformed UTF-8 in the path, affecting every adapter
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 ada…
Published: 2026-09-29 · CVSS: 3.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7