CVE-2026-12993 is a medium-severity (CVSS 6.5) CWE-776 vulnerability in io.apicurio:apicurio-registry-schema-util-xml. A fix is available for io.apicurio:apicurio-registry-schema-util-xml — see the affected versions and patch details below.
Apicurio Registry is vulnerable to denial of service through XML entity expansion
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-12993.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
io.apicurio:apicurio-registry-schema-util-xml☕io.apicurio:apicurio-registry-schema-util-xmlReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.apicurio:apicurio-registry-schema-util-xml | ≥ 3.3.0&&< 3.3.1 | 3.3.1io.apicurio:apicurio-registry-schema-util-xml:3.3.1 |
| ☕Maven | io.apicurio:apicurio-registry-schema-util-xml | all versions | 3.2.6io.apicurio:apicurio-registry-schema-util-xml:3.2.6 |
Affected Products
build of apicurio registryredhatDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.apicurio:apicurio-registry-schema-util-xml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.apicurio:apicurio-registry-schema-util-xml to 3.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-12993 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat build of Apicurio Registry 3.3.1 | apicurio/apicurio-registry-rhel8 | RHSA-2026:59360 |
Frequently Asked Questions
Is CVE-2026-12993 in your dependencies?
Find it across Maven, including transitive dependencies.