CVE-2026-17545

MEDIUMPre-NVD 6.96.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (23rd percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this weekElevated
6.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.9Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
6.9
EG Score
6.9MEDIUMmedium confidence
EG Risk
47
EG Risk 47/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity69% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
23rd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 25, 2026

Last Modified

September 29, 2026

Advisory Details (1)

Auto-updated Sep 25, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

PHP on Windows: Reserved Device Names Are Not Rejected Before File/Stream I/O which can cause DoS · Advisory · php/php-src · GitHub

https://github.com/php/php-src/security/advisories/GHSA-9f67-6fw4-hpfp

Vendor Advisories for CVE-2026-17545(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatphp-main-8.5.11-2.hum12026-09-23redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 20× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-03 21:55 UTCEG score recompute
  2. 2026-10-03 21:55 UTCVendor advisory
  3. 2026-10-03 14:25 UTCEPSS rescore
  4. 2026-10-02 21:54 UTCEG score recompute
  5. 2026-10-02 21:54 UTCVendor advisory
  6. 2026-10-01 22:03 UTCEG score recompute
  7. 2026-10-01 22:03 UTCVendor advisory
  8. 2026-10-01 19:49 UTCEPSS rescore
  9. 2026-09-30 22:07 UTCEG score recompute
  10. 2026-09-30 22:07 UTCVendor advisory
  11. 2026-09-30 15:02 UTCEPSS rescore
  12. 2026-09-29 22:16 UTCEG score recompute
  13. 2026-09-29 22:16 UTCVendor advisory
  14. 2026-09-29 15:20 UTCEPSS rescore
  15. 2026-09-28 20:51 UTCEG score recompute
  16. 2026-09-28 20:51 UTCVendor advisory
  17. 2026-09-28 13:51 UTCEPSS rescore
  18. 2026-09-27 21:00 UTCEG score recompute
  19. 2026-09-27 21:00 UTCVendor advisory
  20. 2026-09-27 13:47 UTCEPSS rescore
  21. 2026-09-26 21:09 UTCEG score recompute
  22. 2026-09-26 21:09 UTCVendor advisory
  23. 2026-09-26 15:58 UTCEPSS rescore
  24. 2026-09-25 21:19 UTCEG score recompute
  25. 2026-09-25 20:51 UTCEG score recompute
Show 2 more
  1. 2026-09-25 20:24 UTCEG score recompute
  2. 2026-09-25 20:24 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-17545?
CVE-2026-17545 is a medium vulnerability published on September 25, 2026. 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…
When was CVE-2026-17545 disclosed?
CVE-2026-17545 was first published on September 25, 2026, with the most recent update on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-17545 actively exploited?
CVE-2026-17545 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (23rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-17545?
CVE-2026-17545 has a CVSS base score of 6.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-17545?
A fix for CVE-2026-17545 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-17545 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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