---
id: CVE-2026-49460
aliases:
  - GHSA-5hgr-hg42-57jg
title: 'pypdf: Inefficient decoding of FlateDecode PNG predictor streams'
summary: 'pypdf: Inefficient decoding of FlateDecode PNG predictor streams'
severity: medium
cwe:
  - CWE-407
vendor: pypdf
product: pypdf
ecosystem: pip
affected:
  - pypdf < 6.12.2
patched:
  - pypdf 6.12.2
published: '2026-06-16'
updated: '2026-06-16'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-5hgr-hg42-57jg'
references:
  - url: 'https://github.com/py-pdf/pypdf/security/advisories/GHSA-5hgr-hg42-57jg'
  - url: 'https://github.com/py-pdf/pypdf/pull/3806'
  - url: 'https://github.com/py-pdf/pypdf/releases/tag/6.12.2'
  - url: 'https://github.com/advisories/GHSA-5hgr-hg42-57jg'
tags:
  - ghsa
  - pip
epss: 0.00166
epssPercentile: 0.0626
ingestedAt: '2026-07-07T15:41:58.389Z'
---

## Overview

### Impact
An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the `/FlateDecode` filter with a PNG predictor.

### Patches
This has been fixed in [pypdf==6.12.2](https://github.com/py-pdf/pypdf/releases/tag/6.12.2).

### Workarounds
If you cannot upgrade yet, consider applying the changes from PR [#3806](https://github.com/py-pdf/pypdf/pull/3806).

## Affected packages

- `pypdf < 6.12.2`

## Remediation

Upgrade to a patched release:

- `pypdf 6.12.2`