A heap-based buffer overflow vulnerability exists in the RPM Package Manager (RPM) due to improper handling of the RPMTAG_FILESIGNATURES header in crafted, unsigned RPM packages. This flaw allows an attacker to cause a buffer overflow by declaring the header with an incorrect type, leading to out-of-bounds memory writes during hex decoding. The issue can be triggered via rpm2cpio, rpm2archive, and rpm -qlvp commands when processing untrusted packages. A fix is available in version 4.18.2-43.oe2403sp1.