---
id: CVE-2026-28351
title: >-
  pypdf: pypdf: Denial of Service via crafted PDF with RunLengthDecode filter
  (CVE-2026-28351)
summary: >-
  A flaw was found in pypdf, a free and open-source pure-python PDF library. An
  attacker can exploit this vulnerability by crafting a malicious PDF file that,
  when parsed, leads to excessive memory consumption. This occurs specifically
  when …
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'
cvssSource: vendor
cwe: CWE-770
vendor: Red Hat
product: OpenShift Lightspeed
affected:
  - openshift_lightspeed
  - openshift_ai_rhoai
patched:
  - pypdf 6.7.4
published: '2026-02-27'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T11:34:35+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28351.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28351.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-28351'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2443450'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-28351'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28351'
  - url: >-
      https://github.com/py-pdf/pypdf/commit/f309c6003746414dc7b5048c19e6d879ff2dc858
  - url: 'https://github.com/py-pdf/pypdf/pull/3664'
  - url: 'https://github.com/py-pdf/pypdf/releases/tag/6.7.4'
  - url: 'https://github.com/py-pdf/pypdf/security/advisories/GHSA-f2v5-7jq9-h8cg'
  - url: 'https://github.com/py-pdf/pypdf'
tags:
  - csaf
  - vex
  - red-hat
  - osv
  - pip
epss: 0.0048
epssPercentile: 0.41233
aliases:
  - GHSA-f2v5-7jq9-h8cg
  - PYSEC-2026-3017
ecosystem: pip
ingestedAt: '2026-07-13T18:57:57.025Z'
---

## Overview

A flaw was found in pypdf, a free and open-source pure-python PDF library. An attacker can exploit this vulnerability by crafting a malicious PDF file that, when parsed, leads to excessive memory consumption. This occurs specifically when processing the content stream using the RunLengthDecode filter. Successful exploitation can result in a Denial of Service (DoS) condition due to large memory usage.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: OpenShift Lightspeed, Red Hat OpenShift AI (RHOAI) · no fix planned: OpenShift Lightspeed, Red Hat OpenShift AI (RHOAI) · updated 2026-10-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28351.json)

**pypdf: pypdf: Denial of Service via crafted PDF with RunLengthDecode filter** — rated Moderate by Red Hat. Released 2026-02-27, updated 2026-10-15.

Affected:

- OpenShift Lightspeed
- Red Hat OpenShift AI (RHOAI)

No fix planned:

- OpenShift Lightspeed
- Red Hat OpenShift AI (RHOAI)

Not affected:

- Red Hat AI Inference Server
- Red Hat Enterprise Linux AI (RHEL AI) 3
- Red Hat Quay 3

## Remediation

Fix deferred

## Package advisory (CVE-2026-28351)

Affected packages:

- `pypdf < 6.7.4`

Patched in:

- `pypdf 6.7.4`

Source: https://osv.dev/vulnerability/GHSA-f2v5-7jq9-h8cg