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📦 npm

CVE-2024-38527

MEDIUM

Cross-site Scripting in ZenUML

Also known asGHSA-q6xv-jm4v-349h
Published
Jun 26, 2024
Updated
Apr 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk30th percentile+0.24%
0.00%0.29%0.59%0.88%0.2%0.4%Dec 25Apr 26Jun 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

@zenuml/corenpm
564Kdownloads / week

Description

ZenUML is JavaScript-based diagramming tool that requires no server, using Markdown-inspired text definitions and a renderer to create and modify sequence diagrams. Markdown-based comments in the ZenUML diagram syntax are susceptible to Cross-site Scripting (XSS). The comment feature allows the user to attach small notes for reference. This feature allows the user to enter in their comment in markdown comment, allowing them to use common markdown features, such as ** for bolded text. However, the markdown text is currently not sanitized before rendering, allowing an attacker to enter a malicious payload for the comment which leads to XSS. This puts existing applications that use ZenUML unsandboxed at risk of arbitrary JavaScript execution when rendering user-controlled diagrams. This vulnerability was patched in version 3.23.25,

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npm@zenuml/coreall versions3.23.25

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @zenuml/core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update @zenuml/core to 3.23.25 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-38527 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether CVE-2024-38527 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2024-38527. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

ZenUML is JavaScript-based diagramming tool that requires no server, using Markdown-inspired text definitions and a renderer to create and modify sequence diagrams. Markdown-based comments in the ZenUML diagram syntax are susceptible to Cross-site Scripting (XSS). The comment feature allows the user to attach small notes for reference. This feature allows the user to enter in their comment in markdown comment, allowing them to use common markdown features, such as `**` for bolded text. However, the markdown text is currently not sanitized before rendering, allowing an attacker to enter a malic
O3 Security · Impact-Aware SCA

Is CVE-2024-38527 in your dependencies?

O3 detects CVE-2024-38527 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

CVE-2024-38527: Cross-site Scripting in ZenUML (Medium 5.4) | O3 Security