| Name | CVE-2026-27026 |
| Description | pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1128690 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| pypdf (PTS) | bookworm | 3.4.1-1+deb12u1 | vulnerable |
| forky, sid, trixie | 5.4.0-1 | vulnerable | |
| pypdf2 (PTS) | bullseye | 1.26.0-4+deb11u1 | vulnerable |
| bookworm | 2.12.1-3+deb12u1 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| pypdf | source | (unstable) | (unfixed) | 1128690 | ||
| pypdf2 | source | (unstable) | (unfixed) |
[bullseye] - pypdf2 <postponed> (minor issue; DoS)
https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h
https://github.com/py-pdf/pypdf/pull/3644
Fixed by: https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016 (6.7.1)
Issue uncovered with the fix for CVE-2025-55197