CVE-2026-22690: Pypdf Pypdf Has Possible Long Runtimes Vulnerability

LOW
Advisory Identifier: GHSA-4xc4-762w-m6cg
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CWE-400
Published
Advisory Summary

CVE-2026-22690 is a LOW pypdf has possible long runtimes vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Pypdf libraries in the PyPI ecosystem. The issue involves pypdf has possible long runtimes for missing /root object with large /size values. Remediation is available by upgrading affected packages to version 6.6.0.

CVE-2026-22690 at a Glance

CVE Identifier CVE-2026-22690
GHSA Identifier GHSA-4xc4-762w-m6cg
Severity LOW
CVSS v3.1 Base Score N/A
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Pypdf
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2026-22690

To remediate this vulnerability, upgrade all affected Pypdf dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pypdf fixed: 6.6.0 
pip install pypdf>=6.6.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show pypdf

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-22690, inspect your installed packages using pip:

pip show pypdf

Analyze the terminal output to locate any version of Pypdf in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.6.0), your application is affected.

Note: The pip show pypdf command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Pypdf, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact An attacker who exploits this vulnerability can craft a PDF which leads to possibly long runtimes for actually invalid files. This can be achieved by omitting the `/Root` entry in the trailer, while using a rather large `/Size` value. Only the non-strict reading mode is affected. ### Patches This has been fixed in [pypdf==6.6.0](https://github.com/py-pdf/pypdf/releases/tag/6.6.0). ### Workarounds ```python from pypdf import PdfReader, PdfWriter # Instead of reader = PdfReader("file.pdf") # use the strict mode: reader = PdfReader("file.pdf", strict=True) # Instead of writer = PdfWriter(clone_from="file.pdf") # use an explicit strict reader: writer = PdfWriter(clone_from=PdfReader("file.pdf", strict=True)) ``` ### Resources This issue has been fixed in #3594.

CVE-2026-22690 Affected Pypdf Versions

1 component(s)
Fixed Versions:
6.6.0
Product / Package Ecosystem Affected Versions Fixed Version
pypdf
pypi/pypdf
PyPI
< 6.6.0
6.6.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/py-pdf/pypdf/security/advisories/GHSA-4xc4-762w-m6cg
NVD — CVE-2026-22690 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-22690
Pypdf Source Repository REPOSITORY
https://github.com/py-pdf/pypdf/pull/3594
Security Fix Commit FIX COMMIT
https://github.com/py-pdf/pypdf/commit/294165726b646bb7799be1cc787f593f2fdbcf45
Pypdf Source Repository REPOSITORY
https://github.com/py-pdf/pypdf
Pypdf Release RELEASE
https://github.com/py-pdf/pypdf/releases/tag/6.6.0

Frequently Asked Questions

What is CVE-2026-22690?
CVE-2026-22690 is a security vulnerability in Pypdf involving pypdf has possible long runtimes for missing /Root object with large /Size values under CWE-400: Uncontrolled Resource Consumption.
Which Pypdf versions are affected?
Affected versions include releases prior to 6.6.0 across affected packages: pypdf.
What version fixes CVE-2026-22690?
Upgrading to 6.6.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pypdf affected?
Yes, pypdf is affected in releases prior to 6.6.0. Upgrade your dependency to 6.6.0 or later.
What CWE is associated with CVE-2026-22690?
CVE-2026-22690 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check PyPI dependencies for CVE-2026-22690?
Run the dependency tree command: 'pip show pypdf'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4xc4-762w-m6cg",
  "modified" : "2026-01-11T14:53:34Z",
  "published" : "2026-01-09T19:48:22Z",
  "aliases" : [ "CVE-2026-22690" ],
  "summary" : "pypdf has possible long runtimes for missing /Root object with large /Size values",
  "details" : "### Impact\nAn attacker who exploits this vulnerability can craft a PDF which leads to possibly long runtimes for actually invalid files. This can be achieved by omitting the `/Root` entry in the trailer, while using a rather large `/Size` value. Only the non-strict reading mode is affected.\n\n### Patches\nThis has been fixed in [pypdf==6.6.0](https://github.com/py-pdf/pypdf/releases/tag/6.6.0).\n\n### Workarounds\n\n```python\nfrom pypdf import PdfReader, PdfWriter\n\n\n# Instead of\nreader = PdfReader(\"file.pdf\")\n# use the strict mode:\nreader = PdfReader(\"file.pdf\", strict=True)\n\n# Instead of\nwriter = PdfWriter(clone_from=\"file.pdf\")\n# use an explicit strict reader:\nwriter = PdfWriter(clone_from=PdfReader(\"file.pdf\", strict=True))\n```\n\n### Resources\nThis issue has been fixed in #3594.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pypdf"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.6.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/py-pdf/pypdf/security/advisories/GHSA-4xc4-762w-m6cg"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-22690"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/py-pdf/pypdf/pull/3594"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/py-pdf/pypdf/commit/294165726b646bb7799be1cc787f593f2fdbcf45"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/py-pdf/pypdf"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/py-pdf/pypdf/releases/tag/6.6.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-01-09T19:48:22Z",
    "nvd_published_at" : "2026-01-10T05:16:01Z"
  }
}