PatchTheCVECVE-2026-119203: pypdf is a free and open-source pure-python PDF library
CVE-2026-119203 is a medium-severity flaw (CVSS 5.5) affecting pypdf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop while opening a crafted incomplete PDF whose standard cross-reference table reaches the end of the file without a trailer. The trailer search can repeatedly rewind to the same stream position instead of terminating when parsing makes no progress, blocking the processing thread. This issue is fixed in version 6.21.4.
Why this priority
- No elevated risk signals yet
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.5 (Medium) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | 0.3% (top 77%) |
| CISA exploited list | No |
| Weakness | CWE-835 |
| Published | 2026-10-29 |
| Last modified | 2026-11-02 |
Last updated 2026-11-02 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- Vulners Bulletins: CVE-2026-119203 2026-10-30
- VulDB Recent Entries: CVE-2026-119203 | py-pdf pypdf up to 6.21.3 infinite loop 2026-10-29
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-119203?
pypdf: upgrade to 6.21.4. Exact commands for each OS are on this page.
Is CVE-2026-119203 being exploited?
CVE-2026-119203 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-119203 affect?
CVE-2026-119203 affects pypdf. Severity is medium (CVSS 5.5). pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop while opening a crafted incomplete PDF whose standard cross-reference table reaches the end of the file without a trailer. The traile
How urgent is CVE-2026-119203?
Priority 25/100. No elevated risk signals yet.
Software pages
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