CVE-2026-102461 Eclipse Foundation CVE debrief

Who should care

Defenders responsible for Vert.x deployments, particularly those using affected versions, should assess exposure and prioritize patching or mitigation to prevent potential denial-of-service attacks.

Why it matters

CVE-2026-102461 is a high-severity vulnerability in Eclipse Vert.x's io.vertx:vertx-json-schema component that can lead to denial of service. Defenders should prioritize assessing exposure and applying patches or mitigations to prevent potential attacks.

• Denial of service due to disproportionate CPU time consumption
• Potential impact on system availability and performance
• Need for patching or mitigation to prevent exploitation
• Verification of JSON schema validation configurations required

Technical summary

The uniqueItems keyword validation in io.vertx:vertx-json-schema uses an O(n²) pairwise comparison loop with no short-circuit or size limit. This allows a remote unauthenticated attacker to submit a moderately-sized JSON array that consumes disproportionate CPU time, leading to denial of service. The impacted versions are [4.0.0, 4.5.34], [5.0.0,5.0.12], [5.1.0,5.1.9], and [5.2.0, 5.2.0]. Defenders should prioritize assessing exposure and applying patches or mitigations to prevent potential denial-of-service attacks.

Defensive priority

Defenders should prioritize assessing exposure and applying patches or mitigations to prevent potential denial-of-service attacks.

Recommended defensive actions

• Assess exposure of Vert.x deployments to CVE-2026-102461
• Apply patches or updates to affected versions
• Monitor for potential denial-of-service attacks
• Review and adjust JSON schema validation configurations
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. Additional information on potential exploitation or impact is limited. Defenders should verify JSON schema validation configurations and assess exposure of Vert.x deployments to CVE-2026-102461. Limited evidence suggests that a remote unauthenticated attacker can submit a moderately-sized JSON array that consumes disproportionate CPU time, leading to denial of service. Further verification is required to confirm affected scope and severity.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.