CVE-2026-102601
Flysystem: WhitespacePathNormalizer's control-character (CorruptedPathDetected) check is bypassed by malformed UTF-8 in the path, affecting every adapter
Description
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.
INFO
Published Date :
Sept. 29, 2026, 4:17 p.m.
Last Modified :
Sept. 29, 2026, 4:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Update Flysystem to version 3.35.3.
- Apply vendor patches if updating is not possible.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-102601.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-102601 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-102601
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-102601 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-102601 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Sep. 29, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N Added CWE CWE-150 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/102xxx/CVE-2026-102601.json">CVE-2026-102601</a> Added Reference https://github.com/thephpleague/flysystem/commit/ef4a9a557d769b5d472c403125716706a0d9cc77 Added Reference https://github.com/thephpleague/flysystem/releases/tag/3.35.3 Added Reference https://github.com/thephpleague/flysystem/security/advisories/GHSA-cxf4-7mrp-vvpr -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 29, 2026
Action Type Old Value New Value Added Reference https://github.com/thephpleague/flysystem/security/advisories/GHSA-cxf4-7mrp-vvpr Added SSVC {'id': 'CVE-2026-102601', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-29T16:01:15.275868Z'}