# 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 e...

Advisory record · `GHSA-9437-39hj-3c93`

- **Identifiers:** `GHSA-9437-39hj-3c93` · `BIT-spark-2026-32773` · `CVE-2026-32773` · `PYSEC-2026-3966`
- **State:** Confirmed
- **Severity:** CVSS 6.1 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-80](https://cwe.mitre.org/data/definitions/80.html)
- **Tags:** [Cross-site scripting (XSS)](https://agentprime.io/advisories/tag/xss.md)
- **Published:** 2 Sept 2026
- **Updated:** 15 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 2 Sept 2026, 11:17 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `pyspark` (PyPI): affected `>=3.0.0, <3.5.8`; fixed in `3.5.8`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The pyspark package versions 3.0.0 up to 3.5.8 (not including 3.5.8) are affected by missing XSS escaping in the Spark History Server. An attacker who can launch a Spark job can inject unescaped frontend code, which may give limited privilege escalation in a browser if a user with higher permissions is tricked into visiting the history page. Upgrade to pyspark 3.5.8 or later.

Written 1 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 6.1 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`, from OSV

- **CISA KEV:** Not listed.
- **EPSS:** 0.0041, the 36th percentile, on 15 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:08 UTC: First seen by agentprime
- 31 Oct 2026, 14:08 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/PYSEC-2026-3966)

## Sources

- [GitHub Advisory Database: GHSA-9437-39hj-3c93](https://github.com/advisories/GHSA-9437-39hj-3c93)
- [OSV: GHSA-9437-39hj-3c93](https://osv.dev/vulnerability/GHSA-9437-39hj-3c93)
- <http://www.openwall.com/lists/oss-security/2026/09/01/4>
- <https://lists.apache.org/thread/k36prh3oxl1z6ov7w8rpmfnt07hmzw3v>
- <https://github.com/advisories/GHSA-9437-39hj-3c93>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-9437-39hj-3c93>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-9437-39hj-3c93/>. Everything for agents: <https://agentprime.io/llms.txt>.