Medium 4.8Published Sep 1, 2026

CVE-2026-84311pypdf: Possible long runtimes/large memory usage when extracting XForm objects

Updated under an hour ago (2026-10-19 08:23 UTC)

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It affects py-pdf pypdf and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for py-pdf pypdf

Exploited in the last 30 days

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.

CVSS: 4.8 MEDIUM (v4.0, CNA)CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Weakness (CWE): CWE-834
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Sep 2, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

py-pdf pypdf py_pdf:pypdf (from the name)	before 6.16.1	CNA record
pypdf_project pypdf pypdf_project:pypdf	before 6.16.1	NVD

References

https://github.com/py-pdf/pypdf/security/advisories/GHSA-763m-79hh-57f2x-refsource-confirm, patch, vendor-advisory
https://github.com/py-pdf/pypdf/pull/3966x-refsource-misc, patch
https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942x-refsource-misc, patch
https://github.com/py-pdf/pypdf/releases/tag/6.16.1x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.