Versions of the package exifreader before 4.39.0 are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) due to decompressing PNG zTXt metadata without enforcing a built-in maximum decompressed output size. When asynchronous parsing is enabled, a crafted PNG file containing a highly compressed zTXt chunk can cause ExifReader to materialize a disproportionately large Comment value in memory.

This affects versions of the package exifreader before 4.39.0. A crafted image containing an ICC mluc tag can set an attacker-controlled record count together with a zero record size. During parsing, ExifReader repeatedly processes the same record and appends entries to an array without sufficient bounds validation, causing excessive memory growth. In applications that parse attacker-supplied images, this may lead to denial of service through memory exhaustion.