The file-upload implementation in rfc1867.c in PHP before 5.4.0 does not properly handle invalid [ (open square bracket) characters in name values, which makes it easier for remote attackers to cause a denial of service (malformed $_FILES indexes) or conduct directory traversal attacks during multi-file uploads by leveraging a script that lacks its own filename restrictions.
Severity
Medium 5.8
Published
24 May 2012
Last changed
16 Jun 2026
Added to UpHeron
14 Oct 2026
Exploit chance
6.2% in the next 30 daysHigher than 93% of CVEs. EPSS by FIRST, 12 Nov 2026