# CVE-2026-12993: Apicurio/apicurio-registry: apicurio-registry: xml entity-expansion denial of service via internal dtd subset

> An attacker with artifact-write permissions can cause CPU and heap exhaustion in Apicurio Registry by uploading XML documents with internal entity-expansion payloads.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Jun 2026
- **Updated:** 25 Aug 2026
- **Also known as:** GHSA-748j-wm96-4wh5

## What is CVE-2026-12993?

CVE-2026-12993 is a medium-severity denial of service vulnerability in Red Hat build of Apicurio Registry 3.3.1, published on 25 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw was found in Apicurio Registry. The DocumentBuilderAccessor correctly blocks external DTD and schema access but does not disable DOCTYPE declarations or enable FEATURE_SECURE_PROCESSING. An attacker with artifact-write permission can upload XML documents with internal entity-expansion payloads (billion-laughs variant) that cause CPU and heap exhaustion, partially mitigated by the JAXP default 64,000 entity-expansion limit.

Weakness: CWE-776 (Improper Restriction of Recursive Entity References in DTDs)

## Which versions are affected by CVE-2026-12993?

It affects 1 product.


Products: Redhat Build of Apicurio Registry.

## How do I fix CVE-2026-12993?

No fix has been published for CVE-2026-12993 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-12993 being exploited?

There is no known exploitation of CVE-2026-12993 in the wild and no public exploit code.

## Other vulnerabilities in Red Hat build of Apicurio Registry 3.3.1

- [CVE-2026-12975](https://insights.sbomify.com/CVE-2026-12975/): XML external entity in Red Hat build of Apicurio Registry 3.3.1 (high 8.5)
- [CVE-2026-12992](https://insights.sbomify.com/CVE-2026-12992/): Apicurio/apicurio-registry: apicurio-registry: ssrf via wsdl4j import dereference in wsdl full validation (high 7.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12993 and fix it if it is affected.

What it is: CVE-2026-12993 is a medium-severity denial of service vulnerability in Red Hat build of Apicurio Registry 3.3.1, published on 25 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-12993 in the wild and no public exploit code.

Affected product: Red Hat build of Apicurio Registry 3.3.1. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-12993/ (Markdown: https://insights.sbomify.com/CVE-2026-12993/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12993
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12993
- OSV: https://osv.dev/vulnerability/CVE-2026-12993

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-12993/
Summaries are generated and may contain mistakes; the official description above is the record.