PHP on Windows: Reserved Device Names Are Not Rejected Before File/Stream I/O which can cause DoS
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.
- Products
- php
- Affected versions
- Not specified
- Fixed versions
- 8.2.34, 8.3.35, 8.4.26, 8.5.11
- CVEs
- CVE-2026-17545
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 10:30 UTC · Revision 2
Source evidence
PHP on Windows: Reserved Device Names Are Not Rejected Before File/Stream I/O which can cause DoS
core-osv · Original sourcePublished 1 Oct 2026, 09:33 UTC
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.
osv:BIT-php-2026-17545
php
Fixed versions: 8.2.34, 8.3.35, 8.4.26, 8.5.11
Complete source record
{
"id": "42ac09bec1e8e6d90703b4bc1e0e1816b806da8b330ae89f9a72bf9b8348395d",
"url": "https://osv.dev/vulnerability/BIT-php-2026-17545",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "PHP on Windows: Reserved Device Names Are Not Rejected Before File/Stream I/O which can cause DoS",
"summary": "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.",
"evidence": "osv:BIT-php-2026-17545",
"products": [
{
"name": {
"value": "php",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "8.2.34",
"evidence": "/affected/0/ranges"
},
{
"value": "8.3.35",
"evidence": "/affected/0/ranges"
},
{
"value": "8.4.26",
"evidence": "/affected/0/ranges"
},
{
"value": "8.5.11",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "BIT-php-2026-17545",
"aliases": [
"BIT-libphp-2026-17545",
"BIT-php-2026-17545",
"BIT-php-min-2026-17545",
"CVE-2026-17545"
],
"affected": [
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "8.2.0"
},
{
"fixed": "8.2.34"
},
{
"introduced": "8.3.0"
},
{
"fixed": "8.3.35"
},
{
"introduced": "8.4.0"
},
{
"fixed": "8.4.26"
},
{
"introduced": "8.5.0"
},
{
"fixed": "8.5.11"
}
]
}
],
"package": {
"name": "php",
"purl": "pkg:bitnami/php",
"ecosystem": "Bitnami"
},
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"database_specific": {
"source": "https://github.com/bitnami/vulndb/tree/main/data/php/BIT-php-2026-17545.json"
}
}
],
"modified": "2026-10-26T08:45:05.587188210Z",
"provider": "osv",
"references": [
"https://github.com/php/php-src/security/advisories/GHSA-9f67-6fw4-hpfp",
"https://nvd.nist.gov/vuln/detail/CVE-2026-17545"
],
"provider_metadata": {
"cpes": [
"cpe:2.3:a:php:php:*:*:*:*:*:*:*:*"
],
"severity": "High"
}
},
"related_cves": [
{
"value": "CVE-2026-17545",
"evidence": "/aliases"
}
],
"security_relevant": true,
"severity_evidence": "/database_specific/severity"
},
"source_id": "core-osv",
"document_id": 446429,
"published_at": "2026-10-01T09:33:50.951+00:00"
}