CVE-2026-55497

Summary (CVE-2026-55497): Cloudreve before 4.17.0 is vulnerable to an unbounded memory allocation during image decoding. The built‑in thumbnail and avatar decoders only cap the compressed file size; they do not limit decoded pixel dimensions for PNG/JPEG/GIF, enabling an authenticated user to sub...

CVE-2026-55497 Cloudreve: Server crash through image decompression/pixel bomb in thumbnail & avatar decoding (DoS)

Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, the built-in thumbnail and avatar image decoders limit compressed file size but do not limit decoded pixel dimensions, allowing an authenticated user to submit a small PNG, JPEG, or GIF that triggers an unbounded...

PYSEC-2026-1615 Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders

Impact In Synapse versions before 1.120.1, enabling the dynamicthumbnails option or processing a specially crafted request could trigger the decoding and thumbnail generation of uncommon image formats, potentially invoking external tools like Ghostscript for processing. This significantly expands...