Integer overflow in Artifex Software Inc. *Pymupdf* Mupdf

CVE-2026-3308

An integer overflow vulnerability in 'pdf-image.c' in Artifex's MuPDF version 1.27.0 allows an attacker to maliciously craft a PDF that can trigger an integer overflow within the 'pdf_load_image_imp' function. This allows a heap out-of-bounds write that could be exploited for arbitrary code execution.

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (8.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 8.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3308: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3308?
CVE-2026-3308 is a high-severity vulnerability in Artifex Software Inc. *Pymupdf* Mupdf, classified under Integer Overflow or Wraparound. CVSS score: 7.8/10. Published 2026-03-31.
How severe is CVE-2026-3308?
High severity. CVSS v3 base score is 7.8 out of 10.