TI-2026-65445 Aliases CVE-2026-102601 GHSA-cxf4-7mrp-vvpr

Flysystem: WhitespacePathNormalizer's control-character (CorruptedPathDetected) check is…

MEDIUM 50CWE-150Published 2026-09-29 · Updated 2026-09-29

Key facts

Attack vector: Network
Privileges required: Low
User interaction: Required
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00337 27th percentileScored 2026-11-07

Fix Fixed flysystem (thephpleague): 3.35.3league/flysystem (Packagist): 3.35.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
thephpleague	flysystem	before 3.35.3	3.35.3	Patch available	CNA
—	league/flysystem (Packagist)	before 3.35.3	3.35.3	Patch available	GHSA-cxf4-7mrp-vvpr

flysystem Vendorthephpleague Affected before 3.35.3 Fixed in 3.35.3 Patch available CNA
league/flysystem (Packagist) Vendor— Affected before 3.35.3 Fixed in 3.35.3 Patch available GHSA-cxf4-7mrp-vvpr

Remediation

Fix · CNA flysystem (thephpleague) Fixed in 3.35.3
Fix · GHSA-cxf4-7mrp-vvpr league/flysystem (Packagist) Fixed in 3.35.3 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-102601
2026-10-03 Alias added: GHSA-cxf4-7mrp-vvpr

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-102601

Other 4

TI-2026-69535 league/commonmark Quadratic DoS via TableStartParser CVSS 4.0HIGH 8.7
TI-2026-50093 league/commonmark: AttributesExtension href/src unsafe-link filter bypass via embedded control bytes CVSS 3.1MEDIUM 6.1
TI-2026-69534 Cross-site scripting in League CommonMark bypasses DisallowedRawHtml CVSS 4.0MEDIUM 5.3
TI-2021-12376 Time-of-check Time-of-use (TOCTOU) Race Condition in league/flysystem CVSS 3.1CRITICAL 9.8
TI-2026-59143 commonmark 1.5.0 before 2.8.4 Denial of Service via Footnote CVSS 4.0HIGH 8.7
TI-2026-59142 commonmark 2.0.0 through 2.8.3 Denial of Service via Slug Collision CVSS 4.0HIGH 8.7

See all 20 →

Sources

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