CVE-2026-76763 Red Hat CVE debrief

Who should care

Security teams, particularly those responsible for managing GraphQL APIs, should be aware of this vulnerability and take steps to mitigate it. This includes patching or updating to a fixed version of io.smallrye/smallrye-graphql, implementing input validation and sanitization for GraphQL queries, and monitoring for suspicious query activity.

Why it matters

CVE-2026-76763 is a high-severity vulnerability in io.smallrye/smallrye-graphql that can lead to denial-of-service (DoS) attacks. Defenders should prioritize patching or mitigating this vulnerability to prevent potential DoS attacks.

• Potential CPU exhaustion or OutOfMemoryError due to large exponent float literals
• Unauthenticated remote attackers can exploit this vulnerability
• Denial-of-service (DoS) attacks can be launched without authentication

Technical summary

The io.smallrye/smallrye-graphql package is vulnerable to a denial-of-service (DoS) attack via large exponent float literals. An unauthenticated remote attacker can exploit this by sending a GraphQL query containing a large exponent float literal, causing CPU exhaustion or an OutOfMemoryError. The vulnerability arises from the number scalar coercion for BigInteger not properly validating the magnitude of float or string inputs. This weakness allows attackers to cause significant resource consumption, leading to denial-of-service conditions. Defenders should prioritize patching or mitigating this vulnerability to prevent potential DoS attacks. This requires immediate attention from security teams, particularly

Defensive priority

Defenders should prioritize patching or mitigating this vulnerability to prevent potential DoS attacks. This requires immediate attention from security teams, particularly those responsible for managing GraphQL APIs.

Recommended defensive actions

• Patch or update to a fixed version of io.smallrye/smallrye-graphql
• Implement input validation and sanitization for GraphQL queries
• Monitor for suspicious GraphQL query activity
• Consider implementing rate limiting or query complexity limits
• 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 source item provide details about the vulnerability, including its description, CVSS score, and affected products. However, the corpus does not establish versions, exploitation, impact, or remediation beyond vendor advisories.

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.