Vulnerability · Published Oct 29, 2026 · Assigned by GitHub_M
CVE-2026-119209pypdf: Possible large memory usage when parsing cross-reference streams
High 7.1
In plain English
A high-severity uncontrolled resource consumption 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 0.3% (higher than 19% 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 6.21.3, pypdf can consume excessive memory while opening a crafted PDF containing cross-reference streams that declare very large entry counts. Highly compressible streams and /Prev chains can multiply the number of parsed entries across a document, while negative /Index counts can bypass the existing per-stream clamp. This issue is fixed in version 6.21.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | pypdf | no fix listed | DEBIAN-CVE-2026-119209 |
| Debian:13 | pypdf | no fix listed | DEBIAN-CVE-2026-119209 |
| Debian:14 | pypdf | 6.21.4-1 | DEBIAN-CVE-2026-119209 |
| Debian:12 | pypdf2 | no fix listed | DEBIAN-CVE-2026-119209 |
| PyPI | pypdf | 6.21.3 | GHSA-x3rh-gjgm-fmqc |
| Ubuntu:24.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-119209 |
| Ubuntu:26.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-119209 |
| Ubuntu:26.10 | pypdf | no fix listed | UBUNTU-CVE-2026-119209 |
Affected products (as reported)
Weakness: CWE-400, CWE-770 · 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-x3rh-gjgm-fmqc x_refsource_CONFIRM
- https://github.com/py-pdf/pypdf/pull/4269 x_refsource_MISC
- https://github.com/py-pdf/pypdf/commit/a93fe3a901fd00af38f0a105c3ba7175fa72dcb4 x_refsource_MISC
- https://github.com/py-pdf/pypdf/releases/tag/6.21.3 x_refsource_MISC