Vulnerability · Published Oct 29, 2026 · Assigned by GitHub_M
CVE-2026-119203pypdf: Possible infinite loop when hitting EOF in standard xref table during trailer search
High 7.1
In plain English
A high-severity infinite loop 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 13% 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 6.21.4, pypdf can enter an infinite loop while opening a crafted incomplete PDF whose standard cross-reference table reaches the end of the file without a trailer. The trailer search can repeatedly rewind to the same stream position instead of terminating when parsing makes no progress, blocking the processing thread. This issue is fixed in version 6.21.4.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | pypdf | no fix listed | DEBIAN-CVE-2026-119203 |
| Debian:13 | pypdf | no fix listed | DEBIAN-CVE-2026-119203 |
| Debian:14 | pypdf | 6.21.4-1 | DEBIAN-CVE-2026-119203 |
| Debian:12 | pypdf2 | no fix listed | DEBIAN-CVE-2026-119203 |
| PyPI | pypdf | 6.21.4 | GHSA-5849-834g-hvw5 |
| Ubuntu:24.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-119203 |
| Ubuntu:26.04:LTS | pypdf | no fix listed | UBUNTU-CVE-2026-119203 |
| Ubuntu:26.10 | pypdf | no fix listed | UBUNTU-CVE-2026-119203 |
Affected products (as reported)
Weakness: CWE-835 · 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-5849-834g-hvw5 x_refsource_CONFIRM
- https://github.com/py-pdf/pypdf/pull/4289 x_refsource_MISC
- https://github.com/py-pdf/pypdf/commit/06593f993789a4b573dd955730c1a7051128bb2a x_refsource_MISC
- https://github.com/py-pdf/pypdf/releases/tag/6.21.4 x_refsource_MISC