Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The pypdf package versions before 6.16.0 are vulnerable. An attacker who crafts a PDF can cause an infinite loop in code that calls TreeObject.insert_child during writing. Upgrade to pypdf 6.16.0 or later.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 6.9 | Medium | 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 | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0019, the 8th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 1 Sept 2026, 20:17 UTC Confirmed by NVD
- 31 Oct 2026, 14:10 UTC First seen by agentprime
- 31 Oct 2026, 14:10 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-jp53-mhqp-8xcg
- OSV: GHSA-jp53-mhqp-8xcg
- github.com/py-pdf/pypdf/security/advisories/GHSA-jp53-mhqp-8xcg
- github.com/py-pdf/pypdf/pull/3964
- github.com/py-pdf/pypdf/commit/c9ba557d565d57c53a0b3a0be06c0a4c29b0559b
- github.com/py-pdf/pypdf
- github.com/py-pdf/pypdf/releases/tag/6.16.0