CVE-2026-89059 Red Hat CVE debrief

Who should care

Defenders responsible for RESTEasy deployments should assess exposure and prioritize patching to prevent potential denial-of-service attacks. Affected deployments should verify and apply patches, monitor systems for potential attacks, and implement compensating controls to limit impact. Security teams and vulnerability management teams should review the CVE record and NVD entry for details on the flaw and its potential impact.

Why it matters

Defenders should care about CVE-2026-89059 because it allows a remote, unauthenticated attacker to cause a denial of service in RESTEasy's IIOImageProvider, potentially disrupting service and impacting system availability. Affected deployments should verify and apply patches, monitor systems for potential attacks, and implement compensating controls to limit impact. Evidence from official sources supports these defensive priorities.

• Denial of service through memory exhaustion
• Potential disruption of service
• Need for verification of patch application
• Possible impact on system availability

Technical summary

The flaw in RESTEasy's IIOImageProvider allows a remote, unauthenticated attacker to send a crafted image declaring enormous dimensions, triggering a large memory allocation and resulting in a denial of service. This issue affects deployments using RESTEasy's IIOImageProvider for image processing. Affected deployments should verify and apply patches, monitor systems for potential attacks, and implement compensating controls to limit impact. The CVE record and NVD entry provide details on the flaw, including its potential impact and affected products.

Defensive priority

Defenders should prioritize verifying and applying patches for RESTEasy's IIOImageProvider to prevent potential denial-of-service attacks.

Recommended defensive actions

• Verify and apply patches for RESTEasy's IIOImageProvider
• Monitor systems for potential denial-of-service attacks
• Implement compensating controls to limit the impact of potential attacks
• 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
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the flaw in RESTEasy's IIOImageProvider, including its potential impact and affected products. Evidence from official sources supports defensive priorities for verifying and applying patches, monitoring systems for potential attacks, and implementing compensating controls to limit impact. Affected deployments should verify and apply patches, monitor systems for potential attacks, and implement compensating controls to limit impact.

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.