CVE-2026-54531
pypdf: Possible infinite loop when processing outlines/bookmarks in writer
Description
### Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. ### Patches This has been fixed in [pypdf==6.13.0](https://github.com/py-pdf/pypdf/releases/tag/6.13.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3830](https://github.com/py-pdf/pypdf/pull/3830).
How to fix CVE-2026-54531
To remediate CVE-2026-54531, upgrade the affected package to a fixed version below.
- PyPI/pypdf—upgrade to 6.13.0 or later
Is CVE-2026-54531 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-54531.
Affected packages (1)
- from 0, < 6.13.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |