CVE-2026-84311: pypdf is a free and open-source pure-python PDF library

Q: How do I fix CVE-2026-84311?

pypdf: upgrade to 6.16.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-84311 being exploited?

CVE-2026-84311 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-84311 affect?

CVE-2026-84311 affects pypdf. Severity is low (CVSS 3.3). 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

Q: How urgent is CVE-2026-84311?

Priority 12/100. No elevated risk signals yet.

Routine

LOW 3.3UPGRADE

CVE-2026-84311 is a low-severity flaw (CVSS 3.3) affecting pypdf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	3.3 (Low)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.1% (top 97%)
CISA exploited list	No
Weakness	CWE-834
Published	2026-09-01
Last modified	2026-10-05

Publisher (CNA): GitHub, Inc. · Vendor: pypdf project

Last updated 2026-10-05 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-01 21:18 UTCPublished CVE record published
2026-10-05 17:42 UTCUpdated Record last modified

pypdf project pypdf UPGRADE

Affected: < 6.16.1

Fixed in: 6.16.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy pypdf || rpm -q pypdf || pypdf --version

2. UPGRADE to 6.16.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade pypdf

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade pypdf

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-84311?

pypdf: upgrade to 6.16.1. Exact commands for each OS are on this page.

Is CVE-2026-84311 being exploited?

CVE-2026-84311 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-84311 affect?

CVE-2026-84311 affects pypdf. Severity is low (CVSS 3.3). 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

How urgent is CVE-2026-84311?

Priority 12/100. No elevated risk signals yet.

Software pages

Python vulnerabilities

Related CVEs

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References

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