pypdf: Manipulated FlateDecode XFA streams can exhaust RAM

CAO 7.5CVE-2026-27888 · GHSA-x7hp-r3qg-r3cj · PYSEC-2026-3027 · Công bố 26/02/2026 · cập nhật 17/06/2026

Tóm tắt nhanh

CVE-2026-27888 là lỗ hổng mức CAO (CVSS 7.5) ảnh hưởng pypdf, pypdf (pypdf project).
Xác suất bị khai thác trong 30 ngày tới (EPSS): 0.40%, cao hơn 34.1% các lỗ hổng khác.
Cách xử lý: cập nhật lên 6.7.3 hoặc mới hơn.

Gói / sản phẩm	Phiên bản bị ảnh hưởng	Phiên bản đã vá
pypdf PyPI	`< 6.7.3`	`6.7.3`
pypdf pypdf_project	`< 6.7.3`	`6.7.3`

Mô tả

Impact

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.

Patches

This has been fixed in pypdf==6.7.3.

Workarounds

If projects cannot upgrade yet, consider applying the changes from PR #3658.

Mô tả của NVD

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.