CVE-2026-32773 is a medium-severity (CVSS 6.1) CWE-80 vulnerability in org.apache.spark:spark-core_2.12. A fix is available for org.apache.spark:spark-core_2.12 — see the affected versions and patch details below.
Apache Spark: XSS Vulnerability in Spark Web 3.5.4
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32773.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-32773 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
org.apache.spark:spark-core_2.12☕org.apache.spark:spark-core_2.13🐍pysparkReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven, PyPI packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.spark:spark-core_2.12 | ≥ 3.0.0&&< 3.5.8 | 3.5.8org.apache.spark:spark-core_2.12:3.5.8 |
| ☕Maven | org.apache.spark:spark-core_2.13 | ≥ 3.0.0&&< 3.5.8 | 3.5.8org.apache.spark:spark-core_2.13:3.5.8 |
| 🐍PyPI | pyspark | ≥ 3.0.0&&< 3.5.8 | 3.5.8pip install --upgrade 'pyspark==3.5.8' |
Affected Products
sparkapacheDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.spark:spark-core_2.12, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.spark:spark-core_2.12 to 3.5.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32773 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat rates this issue Low because exploitation requires privileges to submit a malicious Spark job and interaction by a higher-privilege Spark History Server user.
Restrict Spark job submission and Spark History Server access to trusted users until affected Spark components can be updated.Source: Red Hat security advisory for CVE-2026-32773 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-32773 in your dependencies?
Find it across Maven, PyPI, including transitive dependencies.