CVE-2026-32773 Apache Software Foundation CVE debrief

Who should care

Users of Spark History Server, particularly those with high permissions, should be aware of this vulnerability and take steps to upgrade to Spark 3.5.8 or later. Operators, platform administrators, vulnerability management teams, and security teams should review the vulnerability and plan for mitigation if affected deployments exist in managed environments. Compensating controls and monitoring should be considered for exposed systems while remediation is scheduled and verified. Exceptions should be tracked, and remediated assets should be retested before closing the item, with evidence documented accordingly. Asset inventory and source tracking can help in managing the exposure and remediation process effectively. Rollback and change windows should be planned for updates through normal change control processes where exposure is confirmed. Relevant monitoring, detection, and logs should be checked for exposed assets that need extra review. The vulnerability's impact on security and operational processes should be assessed to ensure proper mitigation and minimize potential damage. Security teams should confirm whether affected product deployments exist in managed environments and assign an owner for follow-up. They should also review compensating controls for exposed systems while remediation is scheduled and verified. Monitoring and detection capabilities should be utilized to identify potential exploitation attempts. Asset inventory management can aid in identifying and prioritizing remediation efforts. Source tracking can help in understanding the origin and scope of the vulnerability. By taking these steps, organizations can effectively manage the risk associated with CVE-2026-32773 and protect their Spark History Server deployments from potential exploitation. It is crucial to stay informed about the vulnerability and its potential impact on the organization's security posture. Regular reviews of the vulnerability management process and communication with stakeholders are essential to ensure a timely and effective response to this and other vulnerabilities. The CVE-2026-32773 vulnerability highlights the importance of keeping software up-to-date and having a

Technical summary

The Spark History Server prior to 3.5.8 lacks XSS escaping, allowing a malicious Spark job to generate arbitrary unescaped frontend code. This could lead to a minimal privilege escalation in the browser. The path to exploit requires both relatively high permissions and tricking a user with higher permissions to log in and visit the Spark history web page. The vulnerability is considered 'low' due to the required conditions for exploitation.

Defensive priority

Upgrade Spark history servers to Spark 3.5.8 or later to address the lack of XSS escaping vulnerability.

Recommended defensive actions

• Upgrade Spark history servers to Spark 3.5.8 or later
• Restrict access to Spark History Server to authorized users
• Monitor Spark History Server logs for suspicious activity
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• 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-2026-32773 record indicates a lack of XSS escaping in the Spark History Server prior to 3.5.8. Users are encouraged to upgrade to Spark 3.5.8 or later. The vulnerability requires both relatively high permissions and tricking a user with higher permissions to log in and visit the Spark history web page. Evidence is limited to the official CVE Program record and NIST NVD detail page.

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.