CVE-2026-62297: ag-psd has uncontrolled memory allocation via declared PSD dimensions (DoS)

ag-psd is a JavaScript library for reading and writing Photoshop Document files. Before the allocation-limit remediation attempt in version 31.0.0, readPsd() commits image and layer buffers from attacker-declared PSD geometry before validating the declarations against the actual available data or sane allocation limits. The psdReader.js implementation sizes off-heap typed arrays using width, height, channels, depth and per-layer rectangles, so a tiny PSD declaring enormous geometry can force multi-gigabyte memory allocation before a later bounds error. The reported 52-byte input on Node 24 produced approximately 3.17 GB peak RSS before a RangeError; under memory pressure the process can be terminated before the error can be caught, and concurrent inputs can exhaust memory. Services reading untrusted PSDs are exposed to denial of service. This differs from genuinely large PSD files whose memory demand is proportional to real input content. Version 31.0.0 adds a composite-image allocation limit, but complete coverage of the separately described layer-rectangle allocation path is not established and requires curator residual/scope review.