Vulnerability · Published Apr 22, 2026 · Assigned by GitHub_M
CVE-2026-41313pypdf: Possible long runtimes for wrong size values in incremental mode
Medium 4.8
In plain English
A medium-severity security flaw in pypdf from py-pdf. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.2 can craft a PDF which leads to long runtimes. This requires loading a PDF with a large trailer `/Size` value in incremental mode. This has been fixed in pypdf 6.10.2. As a workaround, one may apply the changes from the patch manually.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | pypdf | no fix listed | DEBIAN-CVE-2026-41313 |
| Debian:13 | pypdf | no fix listed | DEBIAN-CVE-2026-41313 |
| Debian:14 | pypdf | 6.19.0-1 | DEBIAN-CVE-2026-41313 |
| Debian:12 | pypdf2 | no fix listed | DEBIAN-CVE-2026-41313 |
| PyPI | pypdf | 6.10.2 | GHSA-4pxv-j86v-mhcw |
| PyPI | pypdf | 6.10.2 | PYSEC-2026-3007 |
| Ubuntu:24.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-41313 |
| Ubuntu:25.10 | pypdf | no fix listed | UBUNTU-CVE-2026-41313 |
| Ubuntu:26.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-41313 |
| Ubuntu:26.10 | pypdf | no fix listed | UBUNTU-CVE-2026-41313 |
| Ubuntu:22.04:LTS | pypdf2 | no fix listed | UBUNTU-CVE-2026-41313 |
| Ubuntu:24.04:LTS | pypdf2 | no fix listed | UBUNTU-CVE-2026-41313 |
Affected products (as reported)
Weakness: CWE-834 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-4pxv-j86v-mhcw x_refsource_CONFIRM
- https://github.com/py-pdf/pypdf/pull/3735 x_refsource_MISC
- https://github.com/py-pdf/pypdf/commit/c50a0104cf083356f7c7f5d61410466a57f5c88a x_refsource_MISC
- https://github.com/py-pdf/pypdf/releases/tag/6.10.2 x_refsource_MISC