CVE-2026-59935 pypdf: Possible infinite loop for not terminated inline images (ASCII85 and ASCIIHex filter)
An attacker can cause a denial of service via infinite loop in pypdf by crafting a PDF with unterminated inline images using specific filters.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-59935?
CVE-2026-59935 is a high-severity denial of service vulnerability in Pypdf Project Pypdf, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
pypdf is a free and open-source pure-python PDF library. Prior to 6.14.2, an attacker can craft a PDF with a page content stream containing a not terminated inline image that uses the ASCII85 or ASCIIHex filters, causing an infinite loop during parsing such as when extracting page text. This issue is fixed in version 6.14.2.
Weakness: CWE-835
Which versions are affected by CVE-2026-59935?
3 open source packages ship an affected version, including pypdf. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
pypdf PyPI | All versions | 6.14.2 |
pypdf PyPI | All versions | 6.14.2 |
pypdf PyPI | All versions | 6.14.2 |
Products include Pypdf Project Pypdf.
How do I fix CVE-2026-59935?
Upgrade pypdf to 6.14.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-59935 being exploited?
There is no known exploitation of CVE-2026-59935 in the wild and no public exploit code.
Other vulnerabilities in Pypdf Project Pypdf
- CVE-2026-102993 pypdf: Possible large memory usage when retrieving Roman page labels
- CVE-2026-102994 pypdf: Possible long runtimes/large memory usage when parsing indirect objects
- CVE-2026-102995 pypdf: Possible large memory usage for large /ToUnicode streams (Follow-up 2)
- CVE-2026-102996 pypdf: Possible large memory usage when parsing font data
- CVE-2026-102997 pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
Sources
Also known as CLEANSTART-2026-IT15123, CLSA-2026-1787038637, DEBIAN-CVE-2026-59935, ECHO-c00a-ff37-8bcd, GHSA-g867-7843-wf8q, MINI-2274-p4jv-qg7w and 11 more.