pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which…
GitHub_M·CWE-834·Published 2026-05-28
pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.
pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.
### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with `/W [0 0 0]` values and large `/Size` values. ### Patches This has been fixed in [pypdf==6.12.0](https://github.com/py-pdf/pypdf/releases/tag/6.12.0). ### Workarounds If developers are unable to upgrade their apps immediately, they should consider applying the changes from PR [#3791](https://github.com/py-pdf/pypdf/pull/3791).
### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with `/W [0 0 0]` values and large `/Size` values. ### Patches This has been fixed in [pypdf==6.12.0](https://github.com/py-pdf/pypdf/releases/tag/6.12.0). ### Workarounds If developers are unable to upgrade their apps immediately, they should consider applying the changes from PR [#3791](https://github.com/py-pdf/pypdf/pull/3791).
| Version | Type | Source | Base | Exp | Impact | Vector |
|---|---|---|---|---|---|---|
| 3.1 | Primary | NVD | 3.3 | 1.8 | 1.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L |
| 3.1 | Secondary | GHSA | 3.3 | — | — | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L |
| 4.0 | Primary | cve.org | 5.1 | — | — | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| 4.0 | Primary | cve.org | 5.1 | — | — | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| 4.0 | Secondary | NVD | 5.1 | — | — | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| 4.0 | Secondary | GHSA | 5.1 | — | — | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |