pypdf: Possible long runtimes/large memory usage when extracting XForm objects (CVE-2026-84311) | HOL Guard CVE

Medium severityCVE-2026-84311GHSA-763M-79HH-57F2

pypdf: Possible long runtimes/large memory usage when extracting XForm objects

Answer in brief

CVE-2026-84311 records a Medium severity vulnerability in pypdf: Possible long runtimes/large memory usage when extracting XForm objects. The current sources do not mark it as known exploited. The current feed maps py-pdf/pypdf (generic), pypdf (pip). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 1, 2026Updated Sep 1, 2026Source checked Sep 1, 2026First seen by HOL Sep 1, 2026Material review Sep 1, 2026

Upstream Advisory

Key facts

Risk: Medium
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps py-pdf/pypdf (generic), pypdf (pip). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
py-pdf/pypdfgeneric	< 6.16.1	Not reported
pypdfpip	<6.16.1	6.16.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for py-pdf/pypdf, pypdf.
Review the reported fix. Update pypdf to 6.16.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 1, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.