Quick answers
- Is CVE-2026-17545 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-17545 being exploited in the wild.
- How severe is CVE-2026-17545?
- Informational severity, published 25 September 2026.
- Which products and versions are affected?
- Php before 8.2.34, before 8.3.35, before 8.4.26, before 8.5.11.
- Is there a fix for CVE-2026-17545?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-17545 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-17545?
- Check whether you run Php at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
PHP's filesystem and stream APIs (file_get_contents(), move_uploaded_file(), and related functions) pass user-controlled paths directly to Windows CreateFileW() without validating for reserved device names. Attackers can craft paths containing names like CONIN$ or CON.txt that resolve as devices rather than files; blocking on such devices can exhaust concurrent worker processes. The fix adds validation to reject reserved device name components in paths before I/O operations, though bare device names (NUL, NUL:) are permitted for backward compatibility.
Affected products
- PHP PHP before 8.2.34, before 8.3.35, before 8.4.26, before 8.5.11
Timeline
- 2026-09-25: disclosed: Published on NVD and GitHub Security Advisory