CVE-2025-53837: org.xwiki.rendering:xwiki-rendering-xml has an Eval Injection issue

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.

• 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 0.6%, percentile 50: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 50% of all scored CVEs (moderate). 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.rendering:xwiki-rendering-xml (Maven) < 14.10.2, fixed in 14.10.2. Check your lockfile, including transitive dependencies.

What it is

XWiki Rendering is a generic rendering system that converts textual input in a given syntax (wiki syntax, HTML, etc) into another syntax (XHTML, etc). Prior to versions 14.10.2 and 15.0 RC1, any user who can edit their own user profile or any other document can execute arbitrary script macros including Groovy and Python macros that allow remote code execution including unrestricted read and write access to all wiki contents. The reason is that rendering output is included as content of HTML macros without further escaping and it is thus possible to close the HTML macro and inject script macros that are executed with programming rights. This has been patched in XWiki 14.10.2 and 15.0 RC1 by making sure that rendering output cannot close the surrounding HTML macro. A possible workaround is available. It is, in principle, possible to add escaping to all places where rendering output is used in wiki documents, but at the moment there is no list of them.

From the GitHub advisory

Impact Any user who can edit their own user profile or any other document can execute arbitrary script macros including Groovy and Python macros that allow remote code execution including unrestricted read and write access to all wiki contents. The reason is that rendering output is included as content of HTML macros without further escaping and it is thus possible to close the HTML macro and inject script macros that are executed with programming rights.

This can be demonstrated by adding an object of type XWiki.UIExtensionClass to a document with content {{html wiki="true"}}~{~{~/~h~t~m~l~}~}~ ~{~{~c~a~c~h~e~}~}~{~{~g~r~o~o~v~y~}~}~p~r~i~n~t~l~n~(~1~)~{~{~/~g~r~o~o~v~y~}~}~{~{~/~c~a~c~h~e~}~}{{/html}}, extension point id org.xwiki.platform.html.head, extension id org.xwiki.myuser.test and extension scope "current user". When opening /xwiki/bin/view/Main/?sheet=CKEditor.ContentSheet&xpage=plain where is the URL of the XWiki installation, the output should start with {{/html}} {{cache}}{{groovy}}println(1){{/groovy}}{{/cache}} and not with 1 .

This escaping was always missing at least in XWiki syntax version 2, it is definitely exploitable in XWiki 3.3 Milestone 1 via the user profile (not through extension points), though this has also been fixed by a separate patch, see the advisory. Exploitable extension points include org.xwiki.platform.search.ui.docdoesnotexist which has been added in XWiki 8.3 Milestone 1.

Patches This has been patched in XWiki 14.10.2 and 15.0 RC1 by making sure that rendering output cannot close the surrounding HTML macro.

Workarounds It is in principle possible to add escaping to all places where rendering output is used in wiki documents but at the moment there is no list of them.

Weakness type: CWE-95.

Product: org.xwiki.rendering:xwiki-rendering-xml (Maven) · Assigned by: GitHub_M · Published: 2026-09-18

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• 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 none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.64% probability of exploitation activity in the next 30 days; percentile 50.

Timeline

• 2026-09-18 — CVE record published by GitHub_M
• 2026-09-18 — GitHub-reviewed advisory GHSA-26vp-8gxg-v4pg published (critical)
• 2026-09-21 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-26vp-8gxg-v4pg github.com
2. CVE.org record CVE-2025-53837 cve.org
3. NVD entry CVE-2025-53837 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com
5. jira.xwiki.org jira.xwiki.org
6. jira.xwiki.org jira.xwiki.org
7. jira.xwiki.org jira.xwiki.org

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