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

Status: published. Published: 2026-06-25. Updated: 2026-11-06.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Red Hat / Red Hat build of Apicurio Registry 3.3.1 (apicurio/apicurio-registry-rhel8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat build of Apicurio Registry 3.3.1 (apicurio/apicurio-registry-rhel9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.52% as of 2026-11-05; percentile 44.27%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-776

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:59360 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-12993 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2491692 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-12993; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-12993; retrieved 2026-11-06; source updated Not reported

Revision: c4d7528198b303543dddcf6c9885848dfed53aa3f4931b4e8217a6cc3ed08cc0

Canonical: https://y2.dev/cve/CVE-2026-12993

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.