CVE-2026-113791 pypdf: Possible large memory usage when parsing content streams
Medium 6.0
Published
Updated
Check this codebase for CVE-2026-113791 and fix it if it is affected.
What it is: CVE-2026-113791 is a medium-severity vulnerability in py-pdf pypdf, published on 21 Oct 2026.
Exploitation: There is no known exploitation of CVE-2026-113791 in the wild and no public exploit code.
Affected packages and fixed versions:
- pypdf (PyPI): affected all versions; fixed in 6.21.0
- pypdf (PyPI): affected all versions; fixed in 6.21.0
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2026-113791/ (Markdown: https://insights.sbomify.com/CVE-2026-113791/index.md)
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-113791?
CVE-2026-113791 is a medium-severity vulnerability in py-pdf pypdf, published on 21 Oct 2026.
Official description
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.0, an attacker can craft a PDF containing a content stream with many small operations, causing parsing to consume large amounts of memory. This issue is fixed in version 6.21.0.
Which versions are affected by CVE-2026-113791?
2 open source packages ship an affected version, including pypdf.
| Package | Affected | Fixed in |
|---|---|---|
pypdf PyPI | All versions | 6.21.0 |
pypdf PyPI | All versions | 6.21.0 |
How do I fix CVE-2026-113791?
Upgrade pypdf to 6.21.0 or later.
Is CVE-2026-113791 being exploited?
There is no known exploitation of CVE-2026-113791 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-113791, ECHO-42ce-a9e3-9ad4, GHSA-cgf9-327m-v77c, UBUNTU-CVE-2026-113791.