---
id: CVE-2026-88361
title: >-
  SumatraPDF 3.6.1 contains an integer overflow vulnerability in
  EngineMupdf::BuildPageLabelRec() when parsing PDF PageLabels /Nums entries.
summary: >-
  SumatraPDF 3.6.1 contains an integer overflow vulnerability in
  EngineMupdf::BuildPageLabelRec() when parsing PDF PageLabels /Nums entries.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-190
published: '2026-09-24'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T18:17:31.423'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88361'
references:
  - url: >-
      https://github.com/chenjiefeng2001/sumatrapdf_folked/commit/b22a8c71ddc9de80ece5f88d14b434c20fee912e
    label: cve@mitre.org
  - url: >-
      https://github.com/haimag/sumatrapdf/commit/8b999ff1bf0a8df244e75440682a3fd9a038eb2d
    label: cve@mitre.org
  - url: 'https://github.com/sumatrapdfreader/sumatrapdf/issues/5952'
    label: cve@mitre.org
  - url: 'https://github.com/sumatrapdfreader/sumatrapdf/issues/5952'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-25T18:05:40.308342Z'
ingestedAt: '2026-09-24T15:45:56.664Z'
epss: 0.00166
epssPercentile: 0.05163
---

## Overview

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec() when parsing PDF PageLabels /Nums entries.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.