Is CVE-2026-119203 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-119203 being exploited in the wild.

How severe is CVE-2026-119203?

High severity, with a CVSS score of 4, published 29 October 2026.

Which products and versions are affected?

Pypdf before 6.21.4; pypdf (PyPI) < 6.21.4, ECOSYSTEM:introduced=0,fixed=6.21.4.

Is there a fix for CVE-2026-119203?

Yes. pypdf (PyPI): upgrade to 6.21.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-119203 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-119203?

Check whether you run Pypdf or pypdf (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-119203: pypdf infinite loop in PDF cross-reference parsing

Q: Is there a fix for CVE-2026-119203?

Yes. pypdf (PyPI): upgrade to 6.21.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-119203 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-119203?

Check whether you run Pypdf or pypdf (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-119203 · Severity: high · CVSS 4 · Published 2026-10-29

pypdf is a Python library for reading and writing PDF files. A maliciously crafted incomplete PDF can cause pypdf to enter an infinite loop when parsing the file's cross-reference table, blocking the application thread and preventing further processing. This results in a denial-of-service condition for any application using the library to process untrusted PDFs.

Technologies: Pypdf, pypdf (PyPI). Vendors: Pypdf, PyPI.

Quick answers

Is CVE-2026-119203 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-119203 being exploited in the wild.
How severe is CVE-2026-119203?: High severity, with a CVSS score of 4, published 29 October 2026.
Which products and versions are affected?: Pypdf before 6.21.4; pypdf (PyPI) < 6.21.4, ECOSYSTEM:introduced=0,fixed=6.21.4.
Is there a fix for CVE-2026-119203?: Yes. pypdf (PyPI): upgrade to 6.21.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-119203 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-119203?: Check whether you run Pypdf or pypdf (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

pypdf (PyPI): upgrade to 6.21.4 or later
```
pip install "pypdf>=6.21.4"
```

Technical details

The vulnerability exists in the standard cross-reference table parsing routine (_read_standard_xref_table). When a malformed PDF's xref table reaches end-of-file without a proper trailer keyword, the parser can rewind to the same stream position repeatedly instead of terminating, causing an infinite loop. The fix detects when the parser rewinds to a previously seen position and raises an exception, preventing the denial-of-service.

Affected products

pypdf pypdf before 6.21.4

Identifiers

CVE-2026-119203
GHSA-5849-834g-hvw5

Timeline

2026-10-28: patched: Fix merged in PR #4289
2026-10-29: advisory

References

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