Vulnerability · Published Oct 23, 2026 · Assigned by GitHub_M
CVE-2026-115580pypdf: Possible long runtimes for large xref table header limits
High 7.1
In plain English
A high-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 0.4% (higher than 35% 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. Prior to 6.21.2, an attacker can craft a PDF with a standard cross-reference table whose declared entry count exceeds what the file can contain, causing excessive processing and long runtimes when the file is opened. This issue is fixed in version 6.21.2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | pypdf | no fix listed | DEBIAN-CVE-2026-115580 |
| Debian:13 | pypdf | no fix listed | DEBIAN-CVE-2026-115580 |
| Debian:14 | pypdf | 6.21.4-1 | DEBIAN-CVE-2026-115580 |
| Debian:12 | pypdf2 | no fix listed | DEBIAN-CVE-2026-115580 |
| PyPI | pypdf | 6.21.2 | GHSA-gmh7-3g9r-mjh5 |
| Ubuntu:24.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-115580 |
| Ubuntu:26.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-115580 |
| Ubuntu:26.10 | pypdf | no fix listed | UBUNTU-CVE-2026-115580 |
Affected products (as reported)
Weakness: CWE-834 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-gmh7-3g9r-mjh5 x_refsource_CONFIRM
- https://github.com/py-pdf/pypdf/pull/4239 x_refsource_MISC
- https://github.com/py-pdf/pypdf/commit/a3061e34b169d34478d520f5f049c53cfb1482b2 x_refsource_MISC
- https://github.com/py-pdf/pypdf/releases/tag/6.21.2 x_refsource_MISC