This vulnerability exists in the do_pnm2png function of libpng's pnm2png component, where improper handling of width and height arguments leads to a heap-based buffer overflow. The flaw affects all libpng versions from 1.6.0 through 1.6.55. Exploitation is limited to local attackers with low complexity and no user interaction required. The vulnerability has a CVSS 4.8 (medium) score, reflecting limited attack vector and privileges required. No official patch or vendor advisory is currently available.

Successful exploitation of this vulnerability could allow a local attacker to cause a heap-based buffer overflow, potentially leading to application crashes or arbitrary code execution within the context of the vulnerable application. However, the attack requires local access and low privileges, limiting its impact scope. There is no indication of remote exploitation or widespread active exploitation in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the project has not responded with a fix, users should monitor official libpng channels for updates. Until a patch is available, restrict local access to trusted users and avoid processing untrusted PNM images with the vulnerable pnm2png component.