Skip to content
Fencer Vulns
high 7.5

CVE-2026-17545 json

PHP on Windows: Reserved Device Names Are Not Rejected Before File/Stream I/O which can cause DoS

published 2026-09-24 45 d ago modified 2026-10-26 13 d ago also BIT-libphp-2026-17545 , BIT-php-2026-17545 , BIT-php-min-2026-17545 , EUVD-2026-87329 , GHSA-9f67-6fw4-hpfp

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

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.

Patch / fix

  • bitnami libphp 8.2.34, 8.3.35, 8.4.26, 8.5.11
  • bitnami php 8.2.34, 8.3.35, 8.4.26, 8.5.11
  • bitnami php-min 8.2.34, 8.3.35, 8.4.26, 8.5.11
  • PHP Group PHP 8.2.34, 8.3.35, 8.4.26, 8.5.11
  • php hummingbird 1 8.5.11-2.hum1
  • php-gd hummingbird 1 8.5.11-2.hum1
  • php-cli hummingbird 1 8.5.11-2.hum1
  • php-dba hummingbird 1 8.5.11-2.hum1
  • php-dbg hummingbird 1 8.5.11-2.hum1
  • php-ffi hummingbird 1 8.5.11-2.hum1
  • php-fpm hummingbird 1 8.5.11-2.hum1
  • php-gmp hummingbird 1 8.5.11-2.hum1

red hat advisories RHSA-2026:70720

  • php8 openSUSE Tumbleweed 8.5.11-1.1

opensuse advisories openSUSE-SU-2026:11901-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-17545 updated cvss 5.9

php: PHP: Denial of Service via reserved device names on Windows

  • Red Hat Hardened Images php 8.5.11-2.hum1, php-gd 8.5.11-2.hum1, php-cli 8.5.11-2.hum1, php-dba 8.5.11-2.hum1, php-dbg 8.5.11-2.hum1, php-ffi 8.5.11-2.hum1, +21 more
    fixed: vendor fix RHSA-2026:70720
  • Red Hat Enterprise Linux 6 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +21 more Red Hat Enterprise Linux 7 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +19 more Red Hat Enterprise Linux 8 php, libzip, php-gd, php-cli, php-dba, php-dbg, +30 more Red Hat Enterprise Linux 9 php, php-gd, php-cli, php-dba, php-dbg, php-ffi, +19 more Red Hat Enterprise Linux 10 php 8.3.33-1.el10_2, php8.4 8.4.24-2.el10
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
44 d ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/php/php-src/security/advisories/GHSA-9f67-6fw4-hpfp referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:H
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami libphp
>=8.2.0, <8.2.34
>=8.3.0, <8.3.35
>=8.4.0, <8.4.26
>=8.5.0, <8.5.11
8.2.34
8.3.35
8.4.26
8.5.11
bitnami php
>=8.2.0, <8.2.34
>=8.3.0, <8.3.35
>=8.4.0, <8.4.26
>=8.5.0, <8.5.11
8.2.34
8.3.35
8.4.26
8.5.11
bitnami php-min
>=8.2.0, <8.2.34
>=8.3.0, <8.3.35
>=8.4.0, <8.4.26
>=8.5.0, <8.5.11
8.2.34
8.3.35
8.4.26
8.5.11

Affected products

  • PHP Group PHP

Classification

Weakness
  • CWE-67 Improper Handling of Windows Device Names
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of php/php-src published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.