CVE-2026-31859

MEDIUM EPSS 8.3%
Published Mar 11, 20263mo ago · Modified Jun 17, 20261w ago
6.9 CVSS 4.0
Medium
Find Similar
Published Mar 11, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

Description

Craft is a content management system (CMS). The fix for CVE-2025-35939 in craftcms/cms introduced a strip_tags() call in src/web/User.php to sanitize return URLs before they are stored in the session. However, strip_tags() only removes HTML tags (angle brackets) -- it does not inspect or filter URL schemes. Payloads like javascript:alert(document.cookie) contain no HTML tags and pass through strip_tags() completely unmodified, enabling reflected XSS when the return URL is rendered in an href attribute. This vulnerability is fixed in 5.9.7 and 4.17.3.

CVSS Details

Base Score
6.9
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
8.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-116
CWE-79 Cross-site Scripting Injection

Affected Products 2

VendorProductVersionRange
craftcmscraft_cms*≥4.15.3  –  <4.17.3
craftcmscraft_cms*≥5.7.5  –  <5.9.7

References 1

  • github.com https://github.com/craftcms/cms/security/advisories/GHSA-fvwq-45qv-xvhv
    PatchVendor Advisory

Remediation

  • github.com https://github.com/craftcms/cms/security/advisories/GHSA-fvwq-45qv-xvhv
    PatchVendor Advisory