CVE-2026-55847

Allure Report: Stored XSS via unescaped ANSI helper in status message/trace rendering

• Arbitrary JavaScript execution in the browser of anyone viewing the generated Allure report
• Cookie theft, session hijacking if the report is served from a domain with active sessions (e.g., CI dashboards)
• Data exfiltration, the injected script can read the full report content and send it to an attacker-controlled server
• Attack vectors: A malicious dependency that throws crafted exception messages, a CI pipeline processing test results from untrusted pull requests, or a contributor submitting test files containing XSS payloads
• Allure reports are commonly hosted on CI/CD platforms (Jenkins, GitLab, GitHub Actions artifacts) where session cookies may be present

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2026-55847 has a CVSS score of 6.1 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.39.0); upgrading removes the vulnerable code path.

Kodem intelligence

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Configure AnsiToHtml with escapeForHtml: true to escape HTML entities while preserving ANSI-to-HTML conversion:

import AnsiToHtml from "ansi-to-html";
import {SafeString} from "handlebars/runtime";

const ansiConverter = new AnsiToHtml({
    fg: "black",
    bg: "black",
    newline: true,
    escapeForHtml: true,  // Escape HTML entities in non-ANSI input
});

export default function (input) {
    return new SafeString(ansiConverter.toHtml(input));
};

This is the correct approach because it preserves the ANSI escape sequence → HTML conversion (colored output) while ensuring that any non-ANSI HTML in the input is safely escaped. The alternative of using escapeExpression() on the input would destroy ANSI sequences before they could be converted.

1. What is CVE-2026-55847? CVE-2026-55847 is a medium-severity cross-site scripting (XSS) vulnerability in io.qameta.allure:allure-generator (maven), affecting versions <= 2.38.1. It is fixed in 2.39.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2026-55847? CVE-2026-55847 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of io.qameta.allure:allure-generator are affected by CVE-2026-55847? io.qameta.allure:allure-generator (maven) versions <= 2.38.1 is affected.
4. Is there a fix for CVE-2026-55847? Yes. CVE-2026-55847 is fixed in 2.39.0. Upgrade to this version or later.
5. Is CVE-2026-55847 exploitable, and should I be worried? Whether CVE-2026-55847 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-55847 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-55847? Upgrade io.qameta.allure:allure-generator to 2.39.0 or later.

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