GHSA-g9xf-7f8q-9mcj: pypdf: Possible infinite loop when processing threads/articles in writer
Impact
An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with threads/articles into a writer.
Patches
This has been fixed in pypdf==6.13.1.
Workarounds
If users cannot upgrade yet, consider applying the changes from PR #3839.
Details
Original advisory: https://github.com/advisories/GHSA-g9xf-7f8q-9mcj
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-546510.11% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-54651 | coverage & exploitation status | NVD · CVE.org |
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