CVE-2026-27888
HIGH7.5EPSS 0.06%pypdf: Manipulated FlateDecode XFA streams can exhaust RAM
Published: 2/26/2026Modified: 4/28/2026
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.
Affected packages (3)
- Debian/pypdffrom 0
- Debian/pypdf2from 0
- PyPI/pypdffrom 0, < 6.7.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References (7)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-27888
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-27888
- PATCHhttps://github.com/py-pdf/pypdf
- WEBhttps://github.com/py-pdf/pypdf/commit/7a4c8246ed48d9d328fb596942271da47b6d109c
- WEBhttps://github.com/py-pdf/pypdf/pull/3658
- WEBhttps://github.com/py-pdf/pypdf/releases/tag/6.7.3
- WEBhttps://github.com/py-pdf/pypdf/security/advisories/GHSA-x7hp-r3qg-r3cj