CVE-2026-42140 | Server-Side Request Forgery (SSRF) in PlantUML Macro via 'server' parameter

PlantUML Macro is a macro for rendering UML diagrams from simple textual schemes. Prior to version 2.4.1, the PlantUML Macro is vulnerable to Server-Side Request Forgery (SSRF). The macro allows users to specify an alternative PlantUML server via the server parameter. However, the application does not validate the supplied URL. An attacker can supply an internal IP address or a malicious external URL. The XWiki server will attempt to connect to this URL to "render" the diagram. This issue has been patched in version 2.4.1.

Published: 2026-05-04 Last update: 2026-05-07 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-42140 is rated Low Risk (20/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42140

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-05 0.03%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42140

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
1.3 2.7 [email protected]

Weakness enumeration for CVE-2026-42140

GitHub Security Advisory for CVE-2026-42140

GHSA-42fc-7w97-8vrc · Severity: medium · Ecosystem: maven — XWiki PlantUML Macro Vulnerable to Server-Side Request Forgery (SSRF) via 'server' parameter

Affected software / configurations for CVE-2026-42140

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-42140

cvelogic Threat Intelligence