The vulnerability in libsidplayfp occurs in the function SidTuneBase::acceptSidTune, where an unchecked data offset in the header of a PSID/RSID file can cause a heap out-of-bounds read. Attackers may set the header data offset beyond the file size, leading the library to wrap the length calculation and read up to 64 KiB past the allocated heap buffer. This causes the application using the library to crash, providing a denial‑of‑service vector without disclosing sensitive data.

The flaw affects the libsidplayfp library up to and including version 3.1.1. Any program that loads PSID or RSID files through this library is potentially vulnerable regardless of operating system or platform.

The CVSS score of 6.8 indicates moderate severity, and the EPSS score of less than 1 % suggests a very low likelihood of exploitation in the wild. The vulnerability is not listed in the CISA KEV catalog, and no publicly known exploits are documented. The most likely attack vector involves an adversary supplying a crafted PSID/RSID file that sets an excessive header offset; the library does not perform bounds checking, so the OOB read leads to an application crash. The impact is limited to denial of service, with no evidence of privilege escalation or data exfiltration.