CVE-2026-28804
pypdf: Inefficient decoding of ASCIIHexDecode streams
Description
pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.5, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter. This issue has been patched in version 6.7.5.
INFO
Published Date :
March 6, 2026, 7:16 a.m.
Last Modified :
March 10, 2026, 7:39 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update pypdf to version 6.7.5 or a later version.
- Ensure all PDF processing uses the patched library version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-28804.
| URL | Resource |
|---|---|
| https://github.com/py-pdf/pypdf/commit/648c627d2657447dfb1773412af05a0a5103b98f | Patch |
| https://github.com/py-pdf/pypdf/pull/3666 | Issue Tracking Patch |
| https://github.com/py-pdf/pypdf/releases/tag/6.7.5 | Product Release Notes |
| https://github.com/py-pdf/pypdf/security/advisories/GHSA-9m86-7pmv-2852 | Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-28804 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-28804
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-28804 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-28804 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 10, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CPE Configuration OR *cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:* versions up to (excluding) 6.7.5 Added Reference Type GitHub, Inc.: https://github.com/py-pdf/pypdf/commit/648c627d2657447dfb1773412af05a0a5103b98f Types: Patch Added Reference Type GitHub, Inc.: https://github.com/py-pdf/pypdf/pull/3666 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/py-pdf/pypdf/releases/tag/6.7.5 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/py-pdf/pypdf/security/advisories/GHSA-9m86-7pmv-2852 Types: Patch, Vendor Advisory -
New CVE Received by [email protected]
Mar. 06, 2026
Action Type Old Value New Value Added Description pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.5, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter. This issue has been patched in version 6.7.5. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-407 Added Reference https://github.com/py-pdf/pypdf/commit/648c627d2657447dfb1773412af05a0a5103b98f Added Reference https://github.com/py-pdf/pypdf/pull/3666 Added Reference https://github.com/py-pdf/pypdf/releases/tag/6.7.5 Added Reference https://github.com/py-pdf/pypdf/security/advisories/GHSA-9m86-7pmv-2852