CVE-2026-91867 Apache Software Foundation CVE debrief

Who should care

Defenders and system administrators responsible for Apache Neethi deployments should assess exposure and prioritize remediation based on system configurations and deployment contexts.

Why it matters

CVE-2026-91867 is a denial-of-service vulnerability in Apache Neethi that can lead to system resource exhaustion and impact system availability. Defenders and system administrators should assess exposure and prioritize remediation based on system configurations and deployment contexts.

• Denial-of-service condition due to tied-up calling threads
• Potential for system resource exhaustion
• Need for version 3.2.4 upgrade verification
• Possible impact on system availability

Technical summary

The vulnerability allows a server to keep the fetch alive indefinitely by trickling bytes slowly, tying up the calling thread. This can lead to a denial-of-service condition. The vulnerability can lead to system resource exhaustion and impact system availability. The issue is fixed in version 3.2.4. Assess exposure and prioritize remediation based on system configurations and deployment contexts. The vulnerability has a CVSS score of 4.3 and a severity of MEDIUM. The CVE record was published on 2026-09-21T12:17:25.107Z and has not been modified since then.

Defensive priority

Upgrade to version 3.2.4 to fix the issue. Assess exposure and prioritize remediation based on system configurations and deployment contexts.

Recommended defensive actions

• Upgrade Apache Neethi to version 3.2.4
• Assess exposure based on system configurations and deployment contexts
• Prioritize remediation based on system criticality
• 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 vulnerability detail provide information on the denial-of-service vulnerability in Apache Neethi. The vendor advisory and source reference provide additional context. The vulnerability allows a server to keep the fetch alive indefinitely by trickling bytes slowly, tying up the calling thread. This can lead to a denial-of-service condition. There is no information on known or unknown affected scope, but defenders should verify system configurations and deployment contexts.

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.