Vulnerability · Published Jun 30, 2026 · Assigned by GitHub_M
CVE-2026-57204pypdf: Missing stream length values ignore defined limits
Medium 6.9
In plain English
A medium-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 0.4% (higher than 31% 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 6.13.3, a maliciously crafted PDF can cause DoS. An attacker who uses this vulnerability can craft a PDF which leads to large memory usage, as MAX_DECLARED_STREAM_LENGTH is sometimes ignored. This requires parsing a content stream without a /Length value. This issue has been fixed in version 6.13.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | pypdf | no fix listed | DEBIAN-CVE-2026-57204 |
| Debian:13 | pypdf | no fix listed | DEBIAN-CVE-2026-57204 |
| Debian:14 | pypdf | 6.19.0-1 | DEBIAN-CVE-2026-57204 |
| Debian:12 | pypdf2 | no fix listed | DEBIAN-CVE-2026-57204 |
| PyPI | pypdf | 6.13.3 | GHSA-jm82-fx9c-mx94 |
| Ubuntu:24.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-57204 |
| Ubuntu:25.10 | pypdf | no fix listed | UBUNTU-CVE-2026-57204 |
| Ubuntu:26.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-57204 |
| Ubuntu:26.10 | pypdf | no fix listed | UBUNTU-CVE-2026-57204 |
Affected products (as reported)
Weakness: CWE-400 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-jm82-fx9c-mx94 x_refsource_CONFIRM
- https://github.com/py-pdf/pypdf/releases/tag/6.13.3 x_refsource_MISC