---
id: CVE-2026-48977
title: OpenSlide is a C library for reading whole slide image files
summary: >-
  OpenSlide is a C library for reading whole slide image files. From 3.4.1 until
  4.0.1, OpenSlide's parse_level0_xml() processing in
  src/openslide-vendor-ventana.c accepts nonpositive row or column tile counts
  from a crafted Ventana BIF fi…
severity: high
cvss: 7.7
cvssVector: 'CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'
cwe:
  - CWE-123
  - CWE-823
  - CWE-1284
vendor: openslide
product: openslide
affected:
  - 'openslide >= 3.4.1, < 4.0.1'
published: '2026-09-17'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T18:12:04.247'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48977'
references:
  - url: >-
      https://github.com/openslide/openslide/commit/2be88bd782d9fff46de8e56a99baca523e7917b3
    label: security-advisories@github.com
  - url: 'https://github.com/openslide/openslide/pull/751'
    label: security-advisories@github.com
  - url: 'https://github.com/openslide/openslide/releases/tag/v4.0.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/openslide/openslide/security/advisories/GHSA-mxg2-48g7-fmwc
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48977.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-48977'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-48977'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00296
epssPercentile: 0.2246
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-18T20:07:02.848473Z'
cvssSource: cna
ingestedAt: '2026-09-17T21:29:16.980Z'
scores:
  cna: 7.7
  vendor: 7.5
---

## Overview

OpenSlide is a C library for reading whole slide image files. From 3.4.1 until 4.0.1, OpenSlide's parse_level0_xml() processing in src/openslide-vendor-ventana.c accepts nonpositive row or column tile counts from a crafted Ventana BIF file. The invalid counts produce attacker-controlled relative memory offsets and allow arbitrary values to be written at those offsets, affecting all supported platforms and configurations and resulting in a crash or potential arbitrary code execution. This issue is fixed in version 4.0.1.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48977.json)