Summary
pypdf: Unvalidated JPEG image data loading
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #4222.
Impact
An attacker who uses this vulnerability can craft a PDF which leads to arbitrary image parsers being called. This requires loading an image which claims to use the /DCTDecode filter (JPEG data).
Users which do not have the optional Pillow dependency installed in their environment are not affected.
The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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This has been fixed in pypdf==6.21.1.
Frequently Asked Questions
- What is CVE-2026-113786? CVE-2026-113786 is a low-severity improper input validation vulnerability in pypdf (pip), affecting versions < 6.21.1. It is fixed in 6.21.1. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
- Which versions of pypdf are affected by CVE-2026-113786? pypdf (pip) versions < 6.21.1 is affected.
- Is there a fix for CVE-2026-113786? Yes. CVE-2026-113786 is fixed in 6.21.1. Upgrade to this version or later.
- Is CVE-2026-113786 exploitable, and should I be worried? Whether CVE-2026-113786 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-113786 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-113786? Upgrade
pypdfto 6.21.1 or later.