---
title: "CVE-2026-33137: XWiki Platform has an Unauthenticated XAR Import via REST /wikis/{wikiName}"
url: https://erroneo.us/security/cve/CVE-2026-33137/
description: "CVE-2026-33137 (org.xwiki.platform:xwiki-platform-rest-server (Maven)): XWiki Platform is a generic wiki platform offering runtime services for applications…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-20
date_modified: 2026-05-26
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-33137"
kev: false
cvss: 9.3
epss: 0.00879
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-33137: XWiki Platform has an Unauthenticated XAR Import via REST /wikis/{wikiName}

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.9% , percentile 59: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 59% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes org.xwiki.platform:xwiki-platform-rest-server (Maven) >= 15.10.6, < 16.10.17, fixed in 16.10.17 ; org.xwiki.platform:xwiki-platform-rest-server (Maven) >= 17.0.0-rc-1, < 17.4.9, fixed in 17.4.9 ; org.xwiki.platform:xwiki-platform-rest-server (Maven) >= 17.5.0, < 17.10.3, fixed in 17.10.3 ; org.xwiki.platform:xwiki-platform-rest-server (Maven) >= 18.0.0-rc-1, < 18.1.0-rc-1, fixed in 18.1.0-rc-1 . Check your lockfile, including transitive dependencies.

## What it is

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. XWiki Platform is a generic wiki platform. In versions starting with 15.10.6 and prior to 18.1.0-rc-1, 17.10.3, 17.4.9, and 16.10.17, the POST /wikis/{wikiName} API executes a XAR import without performing any authentication or authorization checks, allowing an unauthenticated attacker to create or update documents in the target wiki. This vulnerability has been patched in XWiki 16.10.17, 17.4.9, 17.10.3, 18.0.1 and 18.1.0-rc-1.

## Affected packages

- Maven `org.xwiki.platform:xwiki-platform-rest-server` >= 15.10.6, < 16.10.17 → fixed: 16.10.17
- Maven `org.xwiki.platform:xwiki-platform-rest-server` >= 17.0.0-rc-1, < 17.4.9 → fixed: 17.4.9
- Maven `org.xwiki.platform:xwiki-platform-rest-server` >= 17.5.0, < 17.10.3 → fixed: 17.10.3
- Maven `org.xwiki.platform:xwiki-platform-rest-server` >= 18.0.0-rc-1, < 18.1.0-rc-1 → fixed: 18.1.0-rc-1

## Affected products (CVE record)

- xwiki xwiki-platform: >= 15.10.6, < 16.10.17, >= 17.0.0-rc-1, < 17.4.9, >= 17.5.0, < 17.10.3, >= 18.0.0-rc-1, < 18.1.0-rc-1

## Severity

- GitHub_M CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`
- GitHub CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.88% probability of exploitation activity in the next 30 days; percentile 59.

## Sources

- [GitHub Advisory GHSA-qrvh-r3f2-9h4r](https://github.com/advisories/GHSA-qrvh-r3f2-9h4r)
- [CVE.org record CVE-2026-33137](https://www.cve.org/CVERecord?id=CVE-2026-33137)
- [NVD entry CVE-2026-33137](https://nvd.nist.gov/vuln/detail/CVE-2026-33137)
- [github.com](https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-qrvh-r3f2-9h4r)
- [github.com](https://github.com/xwiki/xwiki-platform/commit/4b7b95b79256374d487e9ece1dc48f527966990f)
- [jira.xwiki.org](https://jira.xwiki.org/browse/XWIKI-23953)

---
Source page: https://erroneo.us/security/cve/CVE-2026-33137/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt