Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.3, pypdf can take excessive time to retrieve page labels from a crafted PDF containing a flat page-label number tree with many ranges. The page_labels property resolves each page independently and repeatedly scans the same /Nums array from the beginning, causing work to grow with both the page count and the number of label ranges. This issue is fixed in version 6.21.3.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| py-pdf | pypdf | < 6.21.3 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | pypdf | 6.21.4-1 | — |
| Debian 13 | pypdf | No fix yet | — |
| Debian 12 | pypdf +1 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | pypdf | No fix yet | — |
| Ubuntu 26.04 LTS | pypdf | No fix yet | — |
| Ubuntu 24.04 LTS | pypdf | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | python-pypdf | 6.19.0-bp160.3.1 | openSUSE-SU-2026:22219-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | open-webui | 0.12.3-r14 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | pypdf | < 6.21.3 | 6.21.3 | GHSA-42gh-23hr-vphw |
Advisories 1
- openSUSE-SU-2026:22219-1 Security update for python-pypdf SUSE / openSUSE Security Updates · Nov 4, 2026