# Payload: Uploaded XML files could execute same-origin JavaScript

Advisory record · `GHSA-9qpg-3cf8-w33x`

- **Identifiers:** `GHSA-9qpg-3cf8-w33x` · `CVE-2026-105868`
- **State:** Confirmed
- **Severity:** CVSS 8.6 High
- **Critical:** No
- **Weakness (CWE):** [CWE-434](https://cwe.mitre.org/data/definitions/434.html)
- **Tags:** [Unrestricted file upload](https://agentprime.io/advisories/tag/file-upload.md)
- **Published:** 7 Oct 2026
- **Updated:** 7 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 7 Oct 2026, 20:28 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `payload` (npm): affected `<3.90.0 || >=4.0.0-canary.0, <4.0.0-canary.34`; fixed in `3.90.0`, `4.0.0-canary.34`

## Machine-written summary

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

> Payload (npm package payload) versions before 3.90.0 and from 4.0.0-canary.0 up to but not including 4.0.0-canary.34 are affected. Under certain local upload configurations, an uploaded XML file and stylesheet could execute JavaScript in the Payload origin when a logged-in user opens the file. Upgrade to 3.90.0 or 4.0.0-canary.34 or later; as a workaround, disallow XML and XSL uploads.

Written 31 Oct 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

- 8.6 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0016, the 5th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 13:33 UTC: First seen by agentprime
- 31 Oct 2026, 13:33 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-9qpg-3cf8-w33x)

## Sources

- [GitHub Advisory Database: GHSA-9qpg-3cf8-w33x](https://github.com/advisories/GHSA-9qpg-3cf8-w33x)
- [OSV: GHSA-9qpg-3cf8-w33x](https://osv.dev/vulnerability/GHSA-9qpg-3cf8-w33x)
- <https://github.com/payloadcms/payload/security/advisories/GHSA-9qpg-3cf8-w33x>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-105868>
- <https://github.com/payloadcms/payload/commit/a8c3a8e8e2680c96ec4f66f5b3854c5df6c35adf>
- <https://github.com/payloadcms/payload>
- <https://github.com/payloadcms/payload/releases/tag/v3.90.0>

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-9qpg-3cf8-w33x>, 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-9qpg-3cf8-w33x/>. Everything for agents: <https://agentprime.io/llms.txt>.