CVE-2026-17545
MEDIUMDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 31% of all known CVEs.
References
Related Vulnerabilities
Other CWE-67 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-51745 | Critical | 10.0 | 0.8% | - | Fix |
| CVE-2026-27199 | Medium | 5.3 | 0.6% | - | Fix |
| CVE-2025-66221 | Medium | 5.3 | 0.5% | - | Fix |
| CVE-2026-21860 | Medium | 5.3 | 0.5% | - | Fix |
| CVE-2024-35197 | Medium | 5.4 | 0.4% | - | Fix |
| CVE-2026-102598 | Medium | 6.3 | 0.4% | - | Fix |
Common questions
How do I fix CVE-2026-17545?
Upgrade php to 8.2.34 or later.
Is CVE-2026-17545 being actively exploited?
Not that we know of. CVE-2026-17545 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.37% is the estimated probability that it will be exploited in the next 30 days. That is higher than 31% of all scored CVEs.
How severe is CVE-2026-17545?
CVE-2026-17545 has a CVSS v3 base score of 7.5, rated moderate. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-17545 affect?
Published advisories record a fix for php (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-17545
Markdown
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TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-10-23.