CVE-2010-4699: PHP

Medium severity, CVSS 5.0. EPSS: 1.6% chance of exploitation in the next 30 days.

The iconv_mime_decode_headers function in the Iconv extension in PHP before 5.3.4 does not properly handle encodings that are unrecognized by the iconv and mbstring (aka Multibyte String) implementations, which allows remote attackers to trigger an incomplete output array, and possibly bypass spam detection or have unspecified other impact, via a crafted Subject header in an e-mail message, as demonstrated by the ks_c_5601-1987 character set.

Affected products

• PHP PHP: up to and including 5.3.3; version 1.0 only; version 2.0 only; version 2.0b10 only; version 3.0 only; version 3.0.1 only; …

Published 2011-01-18. Last modified 2026-06-16.