Answer in brief
CVE-2026-102601 records a Low severity (CVSS 3.5) vulnerability in Flysystem: WhitespacePathNormalizer's control-character (CorruptedPathDetected) check is bypassed by malformed UTF-8 in the path, affecting every adapter. The current sources do not mark it as known exploited. The current feed maps league/flysystem (composer), thephpleague/flysystem (generic), league/flysystem (packagist). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps league/flysystem (composer), thephpleague/flysystem (generic), league/flysystem (packagist). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| league/flysystemcomposer | <=3.35.2 | 3.35.3 |
| thephpleague/flysystemgeneric | <3.35.3 | 3.35.3 |
| league/flysystempackagist | >=0 <3.35.3 | 3.35.3 |
Published upstream
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 29, 2026
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.
Quoted source text, attributed separately from HOL analysis.