The PCRE2 library is a set of C functions that implement regular expression pattern matching. In version 10.45, a heap-buffer-overflow read vulnerability exists in the PCRE2 regular expression matching engine, specifically within the handling of the (*scs:...) (Scan SubString) verb when combined with (*ACCEPT) in src/pcre2_match.c. This vulnerability may potentially lead to information disclosure if the out-of-bounds data read during the memcmp affects the final match result in a way observable by the attacker. This issue has been resolved in version 10.46.
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().