In PHP versions 7.2.x below 7.2.29, 7.3.x below 7.3.16 and 7.4.x below 7.4.4, while using get_headers() with user-supplied URL, if the URL contains zero (\0) character, the URL will be silently truncated at it. This may cause some software to make incorrect assumptions about the target of the get_headers() and possibly send some information to a wrong server.

In PHP versions 7.3.x below 7.3.16 and 7.4.x below 7.4.4, while using mb_strtolower() function with UTF-32LE encoding, certain invalid strings could cause PHP to overwrite stack-allocated buffer. This could lead to memory corruption, crashes and potentially code execution.

In PHP versions 7.2.x below 7.2.9, 7.3.x below 7.3.16 and 7.4.x below 7.4.4, while parsing EXIF data with exif_read_data() function, it is possible for malicious data to cause PHP to read one byte of uninitialized memory. This could potentially lead to information disclosure or crash.

In PHP versions 7.2.x below 7.2.28, 7.3.x below 7.3.15 and 7.4.x below 7.4.3, when creating PHAR archive using PharData::buildFromIterator() function, the files are added with default permissions (0666, or all access) even if the original files on the filesystem were with more restrictive permissions. This may result in files having more lax permissions than intended when such archive is extracted.

In PHP versions 7.2.x below 7.2.28, 7.3.x below 7.3.15 and 7.4.x below 7.4.3, when using file upload functionality, if upload progress tracking is enabled, but session.upload_progress.cleanup is set to 0 (disabled), and the file upload fails, the upload procedure would try to clean up data that does not exist and encounter null pointer dereference, which would likely lead to a crash.

In PHP versions 7.3.x below 7.3.15 and 7.4.x below 7.4.3, while extracting PHAR files on Windows using phar extension, certain content inside PHAR file could lead to one-byte read past the allocated buffer. This could potentially lead to information disclosure or crash.

PHP 7.x through 7.1.5 allows remote attackers to cause a denial of service (buffer overflow and application crash) or possibly have unspecified other impact via a long string because of an Integer overflow in mysqli_real_escape_string.

PHP 7.1.5 has an Out of bounds access in php_pcre_replace_impl via a crafted preg_replace call.

The zend_string_extend function in Zend/zend_string.h in PHP through 7.1.5 does not prevent changes to string objects that result in a negative length, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact by leveraging a script's use of .= with a long string.

Buffer overflow in the radius_get_vendor_attr function in the Radius extension before 1.2.7 for PHP allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a large Vendor Specific Attributes (VSA) length value.

The parse_str function in (1) PHP, (2) Hardened-PHP, and (3) Suhosin, when called without a second parameter, might allow remote attackers to overwrite arbitrary variables by specifying variable names and values in the string to be parsed. NOTE: it is not clear whether this is a design limitation of the function or a bug in PHP, although it is likely to be regarded as a bug in Hardened-PHP and Suhosin.