# 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.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Sep 2026
- **Updated:** 16 Sep 2026
- **Also known as:** GHSA-gc95-3vw8-vg43

## 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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2026-53752?

2 open source packages ship an affected version, including org.docx4j:docx4j-core.


| Package | Ecosystem | 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.

## Is CVE-2026-53752 being exploited?

There is no known exploitation of CVE-2026-53752 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53752 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-53752 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.docx4j:docx4j-core (Maven): affected all versions; fixed in 11.5.14
- org.docx4j:docx4j-core (Maven): affected all versions; fixed in 11.5.14

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53752/ (Markdown: https://insights.sbomify.com/CVE-2026-53752/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53752
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53752
- OSV: https://osv.dev/vulnerability/CVE-2026-53752

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-53752/
Summaries are generated and may contain mistakes; the official description above is the record.