Cyber Posture

CVE-2026-42197

High
Microsoft: not affectedMSmacOS: not affectedMacLinux: not affectedLnxMobile: not affectedMobNetwork: not affectedNetApplication: not affectedAppOther: affectedOth

Published: 27 May 2026

Published
27 May 2026
Modified
27 May 2026
KEV Added
—
Patch
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CVSS Score 8.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
EPSS Score 0.0003 9.3th percentile
Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-42197 is a high-severity Cross-site Scripting (CWE-79) vulnerability. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique JavaScript (T1059.007); ranked at the 9.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to JavaScript (T1059.007) and 1 other technique.
Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

SI-10 Information Input Validation
addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

SI-15 Information Output Filtering
addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

MITRE ATT&CK Enterprise TechniquesAI

T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
attack.mitre.org →
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
attack.mitre.org →
Why these techniques?

Stored XSS enables arbitrary JavaScript execution in admin browser (T1059.007) and facilitates web session cookie theft for account takeover.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD Description

RELATE is a web-based courseware package. Versions prior to commit 555f0efb1c5bd7531c07cd73724d7e566a81f620 have a stored cross-site scripting vulnerability that allows any enrolled student to execute arbitrary JavaScript in an administrator's browser session, potentially leading to full admin account takeover. The `get_user()`…

more

method in `ParticipationAdmin` renders user-controlled input using `mark_safe` combined with Python's % string formatting. This bypasses Django\'s automatic HTML escaping entirely. The value returned by `get_full_name` is derived directly from the `first_name` and `last_name` fields of the User model. These fields are freely editable by any authenticated user through the profile page (`/profile/`) with no sanitization applied. When an admin views the Participation list in the Django admin panel, the unsanitized value is rendered directly into the HTML response, causing the injected script to execute in the admin's browser. Commit 555f0efb1c5bd7531c07cd73724d7e566a81f620 fixes the issue.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
CWE-79
OWASP Top 10 Web 2025
A05:2025

EU & UK References

References