CVE-2023-46250: pypdf is a free and open-source pure-python PDF library

Routine

MEDIUM 5.1UPGRADE

CVE-2023-46250 is a medium-severity flaw (CVSS 5.1) 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. An attacker who uses a vulnerability present in versions 3.7.0 through 3.16.4 can craft a PDF which leads to an infinite loop. This infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. That is, for example, the case when the pypdf-user manipulates an incoming malicious PDF e.g. by merging it with another PDF or by adding

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.1 (Medium)
Attack vector	Local
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 83%)
CISA exploited list	No
Weakness	CWE-835
Published	2023-10-31
Last modified	2026-11-02

Publisher (CNA): GitHub, Inc. · Vendor: py-pdf

Last updated 2026-11-02 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-10-31 16:15 UTCPublished CVE record published
2026-11-02 16:06 UTCUpdated Record last modified

py-pdf pypdf UPGRADE

Affected: >= 3.7.0 and < 3.17.0

Fixed in: 3.17.0

Safe to downgrade to: a release before 3.7.0

1. Check installed version

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

2. UPGRADE to 3.17.0 (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.

3. If no update is available yet, DOWNGRADE to a release before 3.7.0 (Debian / Ubuntu)

apt-cache madison pypdf sudo apt install pypdf=<VERSION_BEFORE_3.7.0> sudo apt-mark hold pypdf

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pypdf sudo dnf downgrade pypdf-<VERSION_BEFORE_3.7.0> sudo dnf versionlock add pypdf

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2023-46250?

pypdf: upgrade to 3.17.0. Exact commands for each OS are on this page.

Is CVE-2023-46250 being exploited?

CVE-2023-46250 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-2023-46250 affect?

CVE-2023-46250 affects pypdf. Severity is medium (CVSS 5.1). pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions 3.7.0 through 3.16.4 can craft a PDF which leads to an infinite loop. This infinite loop blocks the current process and can ut

How urgent is CVE-2023-46250?

Priority 22/100. No elevated risk signals yet.

Software pages

Python vulnerabilities

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References

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