# CVE-2026-115585: pypdf incomplete remediation causing excessive PDF stream reloads

Source: https://junglewise.ai/threats/cve-2026-115585-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-23. Updated: 2026-10-23  
License: CC BY 4.0 with a link back

CVE-2026-115585 · Severity: high · CVSS 4 · Published 2026-10-23

pypdf is a Python library for reading and manipulating PDF files. A flaw in its handling of malformed PDF cross-reference data causes the library to repeatedly reload entire PDF files during error recovery, which can result in excessively long processing times when processing specially crafted PDFs.

Technologies: [Py-Pdf Pypdf](https://junglewise.ai/threats/technologies/py-pdf-pypdf), [pypdf (PyPI)](https://junglewise.ai/threats/technologies/pypdf). Vendors: [Py-Pdf](https://junglewise.ai/threats/vendors/py-pdf), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-115585 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-115585 being exploited in the wild.

**How severe is CVE-2026-115585?** High severity, with a CVSS score of 4, published 23 October 2026.

**Which products and versions are affected?** Py-Pdf Pypdf prior to 6.21.2; pypdf (PyPI) < 6.21.2, ECOSYSTEM:introduced=0,fixed=6.21.2.

**Is there a fix for CVE-2026-115585?** Yes. pypdf (PyPI): upgrade to 6.21.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-115585 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-115585?** Check whether you run Py-Pdf 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 6.21.2 or later

  ```sh
  pip install "pypdf>=6.21.2"
  ```


## Technical details

The vulnerability is an incomplete remediation for handling repeated malformed cross-reference entries (CVE-2026-115585 references GHSA-55h5-xmcq-c37v). Even when a recovery cache is present, the library still triggers a complete PDF stream reload on each recovery attempt, leading to algorithmic complexity attacks. The fix involves caching invalid object lookups and reading the cross-reference table buffer only once during recovery.

## Affected products

- py-pdf pypdf prior to 6.21.2

## Identifiers

- CVE-2026-115585
- GHSA-jr96-gvgh-j3r4

## Timeline

- 2026-10-23: disclosed
- 2026-10-21: patched

## References

- [https://github.com/py-pdf/pypdf/commit/68a0e5046cc9e14a6c24a21a713f3c7fbde18b4b](https://github.com/py-pdf/pypdf/commit/68a0e5046cc9e14a6c24a21a713f3c7fbde18b4b)
- [https://github.com/py-pdf/pypdf/pull/4240](https://github.com/py-pdf/pypdf/pull/4240)

## Related threats

- [pypdf memory exhaustion in cross-reference stream parsing](https://junglewise.ai/threats/cve-2026-119209-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)
- [pypdf denial of service via forged encrypted PDF page count](https://junglewise.ai/threats/cve-2026-119208-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)
- [pypdf excessive memory consumption in strict mode PDF parsing](https://junglewise.ai/threats/cve-2026-119207-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)
- [pypdf denial of service via crafted page labels](https://junglewise.ai/threats/cve-2026-119206-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)
- [pypdf infinite loop in DictionaryObject cloning](https://junglewise.ai/threats/cve-2026-119205-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)