CVE-2026-32773

Apache Spark History Server allows stored cross-site scripting through unescaped application names

There is a lack of XSS escaping in the Spark History Server prior to 3.5.8 which allows a malicious Spark job to generate arbitrary unescaped frontend code which could lead to a minimal privilege escalation in browser. Users are encouraged to upgrade to Spark 3.5.8 or later.

This CVE is marked as "low" since the path to exploit requires both relatively high permissions (ability to launch a Spark job) and requires tricking a user with higher permissions to log in and visit the Spark history web page.

Users are encouraged to upgrade their Spark history servers to Spark 3.5.8 or later.

CVE-2026-32773 has a CVSS score of 6.1 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.5.8); upgrading removes the vulnerable code path.

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1. What is CVE-2026-32773? CVE-2026-32773 is a medium-severity security vulnerability in pyspark (pip), affecting versions >= 3.0.0, < 3.5.8. It is fixed in 3.5.8.
2. How severe is CVE-2026-32773? CVE-2026-32773 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2026-32773?
   • pyspark (pip) (versions >= 3.0.0, < 3.5.8)
   • org.apache.spark:spark-core_2.12 (maven) (versions >= 3.0.0, < 3.5.8)
   • org.apache.spark:spark-core_2.13 (maven) (versions >= 3.0.0, < 3.5.8)
4. Is there a fix for CVE-2026-32773? Yes. CVE-2026-32773 is fixed in 3.5.8. Upgrade to this version or later.
5. Is CVE-2026-32773 exploitable, and should I be worried? Whether CVE-2026-32773 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-32773 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-32773?
   • Upgrade pyspark to 3.5.8 or later
   • Upgrade org.apache.spark:spark-core_2.12 to 3.5.8 or later
   • Upgrade org.apache.spark:spark-core_2.13 to 3.5.8 or later

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