CVE-2026-48155: pypdf: Possible large memory usage for large offsets for layout mode text

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-28 · updated 2026-10-14
Weakness: CWE-400

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires extracting text in layout mode with large character offsets. This vulnerability is fixed in 6.12.0.

Affected products

py-pdf pypdf: before 6.12.0 — fixed in 6.12.0

How to fix

Upgrade to a fixed version: py-pdf pypdf 6.12.0. Check the vendor advisory for mitigations.

References

https://github.com/py-pdf/pypdf/pull/3790
https://github.com/py-pdf/pypdf/releases/tag/6.12.0
https://github.com/py-pdf/pypdf/security/advisories/GHSA-cj93-chg6-vgv8

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