CVE-2026-71870
pypdf: Possible large memory usage for large /ToUnicode streams
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, a crafted PDF can cause large memory consumption when pypdf/_cmap.py function parse_bfrange parses unusually large source-code or destination-string tokens in a font /ToUnicode CMap during text extraction. This issue is fixed in 6.15.0.
INFO
Published Date :
Aug. 7, 2026, 8:16 p.m.
Last Modified :
Aug. 7, 2026, 8:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-71870
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update pypdf to version 6.15.0.
- Use a newer version of the pypdf library.
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-2026-71870.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-71870 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-2026-71870
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-2026-71870 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-71870 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.
-
New CVE Received by [email protected]
Aug. 07, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'py-pdf', 'product': 'pypdf', 'versions': [{'status': 'affected', 'version': '< 6.15.0'}]}] Added Description pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, a crafted PDF can cause large memory consumption when pypdf/_cmap.py function parse_bfrange parses unusually large source-code or destination-string tokens in a font /ToUnicode CMap during text extraction. This issue is fixed in 6.15.0. Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:P/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-400 Added Reference https://github.com/py-pdf/pypdf/commit/afba8080e19d29a3c256a742b340995e695b35aa Added Reference https://github.com/py-pdf/pypdf/pull/3944 Added Reference https://github.com/py-pdf/pypdf/releases/tag/6.15.0 Added Reference https://github.com/py-pdf/pypdf/security/advisories/GHSA-fp3f-mc75-235c