What’s Vulnerable › Vulnerabilities

CVE-2026-113789: pypdf: Possible long runtimes/large memory usage when retrieving form fields

• Severity: medium (CVSS 6.0 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-21 · updated 2026-10-28
• Weakness: CWE-400

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.0, an attacker can craft a PDF that causes large memory usage or long runtimes when an application retrieves the document's form fields. This issue is fixed in version 6.21.0.

Affected products

• py-pdf pypdf: before 6.21.0

References

• https://github.com/py-pdf/pypdf/commit/5ef728f0e16d225c853e89f861ba0a67402fe3f2
• https://github.com/py-pdf/pypdf/pull/4219
• https://github.com/py-pdf/pypdf/releases/tag/6.21.0
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-6vvc-x485-93v7

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