Executive brief
A vulnerability exists in the Artifex jbig2dec library, which is used for decoding JBIG2 images in software like MuPDF and Ghostscript. By providing a specially crafted image file, an attacker can cause the application to crash, leading to a denial of service. This could disrupt operations for users or automated systems processing document files.
Technical details
An integer overflow vulnerability exists in the jbig2_arith_iaid_ctx_new() function within jbig2_arith_iaid.c of the jbig2dec library. The flaw is rooted in insufficient validation of the SBSYMCODELEN parameter, which triggers a signed integer overflow during the decoding loop in jbig2_arith_iaid_decode(). An attacker can exploit this by providing a malicious JBIG2 image file to a linked application (such as MuPDF), resulting in out-of-bounds memory access and a subsequent application crash. The issue was addressed in commit cc37d09.
Affected products
- Artifex Software jbig2dec Prior to commit cc37d09
- Artifex Software MuPDF
Timeline
- 2026-07-06: other: Vulnerability details shared via GitHub Gist
- 2026-07-09: disclosed: CVE published to NVD