CVE-2026-27888

moderate-risk
Published 2026-02-26

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.

Do I need to act?

-
0.05% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
7
CVSS 7.5/10 High
NETWORK / LOW complexity

Affected Products (1)

Affected Vendors

Pypdf Project

References (4)

Patch https://github.com/py-pdf/pypdf/commit/7a4c8246ed48d9d328fb596942271da47b6d109c
Issue Tracking https://github.com/py-pdf/pypdf/pull/3658
Product https://github.com/py-pdf/pypdf/releases/tag/6.7.3
Patch https://github.com/py-pdf/pypdf/security/advisories/GHSA-x7hp-r3qg-r3cj
31
/ 100
moderate-risk
Severity 26/34 · High
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal