Security Digest · Vulnerability record
CVE-2025-46558: org.xwiki.contrib.markdown:syntax-markdown-commonmark12 vulnerable to XSS via Markdown content
XWiki Contrib's Syntax Markdown allows importing Markdown content into wiki pages and creating wiki content in Markdown.
CVSS 9.1 Critical EPSS 0.5% · p40
Should you act?
Critical, preconditions apply
Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.5%, percentile 40: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 40% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes
org.xwiki.contrib.markdown:syntax-markdown-commonmark12(Maven) >= 8.2, < 8.9, fixed in 8.9. Check your lockfile, including transitive dependencies.
What it is
XWiki Contrib's Syntax Markdown allows importing Markdown content into wiki pages and creating wiki content in Markdown. In versions starting from 8.2 to before 8.9, the Markdown syntax is vulnerable to cross-site scripting (XSS) through HTML. In particular, using Markdown syntax, it's possible for any user to embed Javascript code that will then be executed on the browser of any other user visiting either the document or the comment that contains it. In the instance that this code is executed by a user with admins or programming rights, this issue compromises the confidentiality, integrity and availability of the whole XWiki installation. This issue has been patched in version 8.9.
From the GitHub advisory
Impact The Markdown syntax is vulnerable to XSS through HTML. In particular, using Markdown syntax, it's possible for any user to embed Javascript code that will then be executed on the browser of any other user visiting either the document or the comment that contains it. In the instance that this code is executed by a user with admins or programming rights, this issue compromises the confidentiality, integrity and availability of the whole XWiki installation.
To reproduce, on an instance where the CommonMark Markdown Syntax 1.2 extension is installed, log in as a user without script rights. Edit a document and set its syntax to Markdown. Then , add the content alert("XSS") and refresh the page. If an alert appears containing "XSS", then the instance is vulnerable.
Patches This has been patched in version 8.9 of the CommonMark Markdown Syntax 1.2 extension.
Workarounds We're not aware of any workaround except upgrading.
References https://jira.xwiki.org/browse/MARKDOWN-80 https://github.com/xwiki-contrib/syntax-markdown/commit/d136472d6e8a47981a0ede420a9096f88ffa5035
Weakness type: CWE-79.
Product: org.xwiki.contrib.markdown:syntax-markdown-commonmark12 (Maven) · Assigned by: GitHub_M · Published: 2025-04-30
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Maven | org.xwiki.contrib.markdown:syntax-markdown-commonmark12 | >= 8.2, < 8.9 | 8.9 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| xwiki-contrib | syntax-markdown | >= 8.2, < 8.9 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 9.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: low (any account)
- User interaction: required (a user must click/open something)
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.48% probability of exploitation activity in the next 30 days; percentile 40.
Timeline
- — CVE record last updated
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-8g2j-rhfh-hq3r published (critical)
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-8g2j-rhfh-hq3r github.com
- CVE.org record CVE-2025-46558 cve.org
- NVD entry CVE-2025-46558 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
- jira.xwiki.org jira.xwiki.org