---
title: "CVE-2026-102998: pypdf - Denial of Service"
description: "pypdf < 6.19.0 contains a denial of service caused by inefficient appearance-stream generation in _appearance_stream.py when processing crafted PDFs with form field values, letting attackers cause excessive runtimes and application unavailability, exploit requires crafted PDF with form fields."
url: https://panop.io/threat-heartbeat/CVE-2026-102998/
---

# CVE-2026-102998 pypdf - Denial of Service

pypdf < 6.19.0 contains a denial of service caused by inefficient appearance-stream generation in \_appearance\_stream.py when processing crafted PDFs with form field values, letting attackers cause excessive runtimes and application unavailability, exploit requires crafted PDF with form fields.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.34% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-102998)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Published

30 September 2026

Updated

15 October 2026

Weakness

[CWE-400](https://cwe.mitre.org/data/definitions/400.html)

## Vendor fix

Update to version 6.19.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-102998](https://nvd.nist.gov/vuln/detail/CVE-2026-102998)
- [https://github.com/py-pdf/pypdf/security/advisories/GHSA-php9-fj8v-98fj](https://github.com/py-pdf/pypdf/security/advisories/GHSA-php9-fj8v-98fj)
- [https://github.com/py-pdf/pypdf/commit/959467a9b95be83e2dc5ae873ece5f371263ede7](https://github.com/py-pdf/pypdf/commit/959467a9b95be83e2dc5ae873ece5f371263ede7)
- [https://github.com/py-pdf/pypdf/pull/4087](https://github.com/py-pdf/pypdf/pull/4087)
- [https://github.com/py-pdf/pypdf/releases/tag/6.19.0](https://github.com/py-pdf/pypdf/releases/tag/6.19.0)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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