CVE-2026-53752 docx4j: Stack Overflow via Cyclic `w:basedOn` Style Chain leads to Denial of Service
Attackers can cause denial of service in applications using docx4j by submitting DOCX files with cyclic style definitions, triggering stack overflow errors.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53752?
CVE-2026-53752 is a high-severity denial of service vulnerability in org.docx4j docx4j, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
docx4j is an open source Java library for creating, editing, and saving OpenXML packages, including DOCX, PPTX, and XLSX files. Prior to 11.5.14, PropertyResolver and adjacent helpers recursively follow the WordprocessingML w:basedOn style inheritance chain without cycle detection. A well-formed DOCX containing mutually based styles causes unbounded recursion in PropertyResolver.fillPPrStack and related effective-style resolution paths, resulting in StackOverflowError. Server-side conversion and table-of-contents processing of an untrusted document can terminate a worker thread, degrade a thread pool, or deny service, although isolation in disposable workers or safe containment of StackOverflowError can reduce the practical effect. The fix adds cyclic-style tracking and CyclicStylesException handling. This issue is fixed in version 11.5.14.
Which versions are affected by CVE-2026-53752?
2 open source packages ship an affected version, including org.docx4j:docx4j-core.
| Package | Affected | Fixed in |
|---|---|---|
org.docx4j:docx4j-core Maven | All versions | 11.5.14 |
org.docx4j:docx4j-core Maven | All versions | 11.5.14 |
How do I fix CVE-2026-53752?
Upgrade org.docx4j:docx4j-core to 11.5.14 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-2026-53752 being exploited?
There is no known exploitation of CVE-2026-53752 in the wild and no public exploit code.
Sources
Also known as GHSA-gc95-3vw8-vg43.