CVE-2026-12600: high-severity vulnerability in Poppler Innodata Labs

Denial-of-service (DoS) vulnerability in the internal JPEG2000 (JPX) decoding implementation of the Poppler fork developed by Innodata Labs. When an application processes an untrusted PDF file containing specially crafted JPXDecode images, a remote attacker can cause uncontrolled memory consumption. The flaw occurs in the JPXStream::readCodestream() function, where values controlled from the SIZ segment (such as img.nComps) are used for the memory allocation of tiles and components without adequate validation. This allows an attacker to force excessive memory allocation and cause a resource exhaustion, ultimately causing the pdftoppm process to terminate due to out-of-memory (OOM) conditions.