EUVD-2026-43085
GHSA-9wh5-5mcm-hf2j
Severity by source
AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Network-accessible CMS requiring low-privilege auth to inject; victim interaction required for execution; scope change reflects browser origin boundary crossing with limited C and I impact.
Primary rating from Vendor (drupal).
CVSS VectorVendor: drupal
Lifecycle Timeline
5DescriptionCVE.org
Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting") vulnerability in Drupal Drupal core allows Cross-Site Scripting (XSS). This issue affects Drupal core versions: from 0.0.0 to 10.5.12, from 10.6.0 to 10.6.11, from 11.2.0 to 11.2.14, from 11.3.0 to 11.3.12, from 0.0.0 to 11.0.*, from 0.0.0 to 11.1.*.
AnalysisAI
Cross-site scripting (XSS) in Drupal Core affects a broad swath of the 10.x and 11.x release lines, enabling an authenticated low-privileged attacker to inject malicious client-side script that executes in the browser of a victim who interacts with the crafted content. The CVSS scope-change indicator (S:C) confirms the impact escapes the originating component into the victim's browser context, enabling session hijacking or privilege escalation against higher-privileged users. No public exploit code has been identified and EPSS sits at 0.15% (5th percentile), indicating low automated exploitation probability at time of analysis, though the wide deployment footprint of Drupal still makes patching urgent.
Technical ContextAI
CWE-79 (Improper Neutralization of Input During Web Page Generation) describes a failure to sanitize or encode user-controlled strings before they are written into HTML output, allowing injected JavaScript to execute in the victim's browser. The CPE string cpe:2.3:a:drupal:drupal_core identifies the affected component as the Drupal PHP-based CMS framework itself - not a contributed module - meaning the flaw is present across all default installations within the vulnerable version ranges. The CVSS vector's S:C (Changed Scope) metric is consistent with a stored or reflected XSS that crosses the boundary from the Drupal application context into the victim's browser security origin, a classic pattern for CWE-79 in server-rendered CMSes. The specific input field, theme layer, or API endpoint within Drupal core that fails to neutralize input is not disclosed in available data.
RemediationAI
Patch is available per the official Drupal Security Advisory SA-CORE-2026-009 at https://www.drupal.org/sa-core-2026-009. Site owners should consult that advisory for the precise patched versions for their release branch and upgrade immediately; the input data confirms patch availability from the vendor but does not specify exact fixed version numbers, so the advisory page is the authoritative source. For sites running the 11.0.x or 11.1.x branches, which appear to be fully affected with no patched release in the provided data, upgrading to a currently-supported minor branch (11.2.x or 11.3.x) is strongly recommended. As a compensating control while patching is underway, restricting content-creation and editing permissions to only trusted, fully-vetted accounts reduces the PR:L attack surface; however, this is not a substitute for patching since it relies on access-control enforcement rather than fixing the underlying neutralization failure. Enabling a web application firewall rule that filters common XSS payloads in POST bodies can add a detection layer but may produce false positives on legitimate rich-text content.
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Same weakness CWE-79 – Cross-site Scripting (XSS)
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External POC / Exploit Code
Leaving vuln.today