PHP up to 8.2.33/8.3.34/8.4.25/8.5.10 Filesystem CreateFileW input validation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.0$0-$5k0.00+

Summaryinfo

A vulnerability was found in PHP up to 8.2.33/8.3.34/8.4.25/8.5.10 and classified as critical. This affects the function CreateFileW of the component Filesystem. Such manipulation leads to input validation. This vulnerability is documented as CVE-2026-17545. The attack can be executed remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in PHP up to 8.2.33/8.3.34/8.4.25/8.5.10. Affected by this issue is the function CreateFileW of the component Filesystem. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is confidentiality, integrity, and availability. CVE summarizes:

On Windows, PHP's filesystem and stream APIs do not reject reserved device names such as CON, PRN, AUX, NUL, COM1 to COM9, LPT1 to LPT9, CONIN$ and CONOUT$ when they appear as a component of a path. An attacker-controlled filename therefore reaches CreateFileW() and opens a device instead of the regular file the application expected, which can block or hang the request and exhaust worker processes.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-17545 since 07/27/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/25/2026).

Upgrading to version 8.2.34, 8.3.35, 8.4.26 or 8.5.11 eliminates this vulnerability.

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Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: PHP 8.2.34/8.3.35/8.4.26/8.5.11

Timelineinfo

07/27/2026 CVE reserved
09/25/2026 +60 days Advisory disclosed
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Product: php.org

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-17545 (🔒)
GCVE (CVE): GCVE-0-2026-17545
GCVE (VulDB): GCVE-100-410456

Entryinfo

Created: 09/25/2026 22:29
Changes: 09/25/2026 22:29 (68)
Complete: 🔍
Cache ID: 216::103

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