In PHP versions:8.1.* before 8.1.34, 8.2.* before 8.2.30, 8.3.* before 8.3.29, 8.4.* before 8.4.16, 8.5.* before 8.5.1, the getimagesize() function may leak uninitialized heap memory into the APPn segments (e.g., APP1) when reading images in multi-chunk mode (such as via php://filter). This occurs due to a bug in php_read_stream_all_chunks() that overwrites the buffer without advancing the pointer, leaving tail bytes uninitialized. This may lead to information disclosure of sensitive heap data and affect the confidentiality of the target server.
In PHP versions:8.1.* before 8.1.34, 8.2.* before 8.2.30, 8.3.* before 8.3.29, 8.4.* before 8.4.16, 8.5.* before 8.5.1, a heap buffer overflow occurs in array_merge() when the total element count of packed arrays exceeds 32-bit limits or HT_MAX_SIZE, due to an integer overflow in the precomputation of element counts using zend_hash_num_elements(). This may lead to memory corruption or crashes and affect the integrity and availability of the target server.
In PHP versions 8.1.* before 8.1.34, 8.2.* before 8.2.30, 8.3.* before 8.3.29, 8.4.* before 8.4.16, 8.5.* before 8.5.1 when using the PDO PostgreSQL driver with PDO::ATTR_EMULATE_PREPARES enabled, an invalid character sequence (such as \x99) in a prepared statement parameter may cause the quoting function PQescapeStringConn to return NULL, leading to a null pointer dereference in pdo_parse_params() function. This may lead to crashes (segmentation fault) and affect the availability of the target server.
In PHP versions:8.1.* before 8.1.33, 8.2.* before 8.2.29, 8.3.* before 8.3.23, 8.4.* before 8.4.10 some functions like fsockopen() lack validation that the hostname supplied does not contain null characters. This may lead to other functions like parse_url() treat the hostname in different way, thus opening way to security problems if the user code implements access checks before access using such functions.
In PHP versions:8.1.* before 8.1.33, 8.2.* before 8.2.29, 8.3.* before 8.3.23, 8.4.* pgsql and pdo_pgsql escaping functions do not check if the underlying quoting functions returned errors. This could cause crashes if Postgres server rejects the string as invalid.
In PHP versions:8.1.* before 8.1.33, 8.2.* before 8.2.29, 8.3.* before 8.3.23, 8.4.* before 8.4.10 when parsing XML data in SOAP extensions, overly large (>2Gb) XML namespace prefix may lead to null pointer dereference. This may lead to crashes and affect the availability of the target server.
In PHP from 8.1.* before 8.1.32, from 8.2.* before 8.2.28, from 8.3.* before 8.3.19, from 8.4.* before 8.4.5, when receiving headers from HTTP server, the headers missing a colon (:) are treated as valid headers even though they are not. This may confuse applications into accepting invalid headers.
In PHP from 8.1.* before 8.1.32, from 8.2.* before 8.2.28, from 8.3.* before 8.3.19, from 8.4.* before 8.4.5, when user-supplied headers are sent, the insufficient validation of the end-of-line characters may prevent certain headers from being sent or lead to certain headers be misinterpreted.
In PHP from 8.1.* before 8.1.32, from 8.2.* before 8.2.28, from 8.3.* before 8.3.19, from 8.4.* before 8.4.5, when requesting a HTTP resource using the DOM or SimpleXML extensions, the wrong content-type header is used to determine the charset when the requested resource performs a redirect. This may cause the resulting document to be parsed incorrectly or bypass validations.
In PHP from 8.1.* before 8.1.32, from 8.2.* before 8.2.28, from 8.3.* before 8.3.19, from 8.4.* before 8.4.5, when http request module parses HTTP response obtained from a server, folded headers are parsed incorrectly, which may lead to misinterpreting the response and using incorrect headers, MIME types, etc.