CVE-2026-115935

Control panel only API response emulation replaces "securityKey" and reaches server RCE

HIGH
8.8
CVSS Score
Published: October 23, 2026 at 09:40 PM UTC
Updated: October 26, 2026 at 06:39 PM UTC
1 product affected across 1 vendorCraftcms

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Severity
HIGH8.8
Exploit prediction
EPSS 0.4%

Description

The app/process-api-response-headers action accepts fake Craft API response headers from any authenticated control panel user. A non-admin user with only accessCp can place newline characters in X-Craft-Plugin-Licenses. Craft passes this value to its .env writer without removing the newlines. This lets the user insert a new attacker-known CRAFT_SECURITY_KEY into .env. After Craft loads that key, the user can forge a signed login redirect containing a Twig system() callback. This is different from the previous report. That report reads the existing key through a Twig sandbox bypass. This report replaces the key through fake API headers and CRLF injection. Fixing either source does not fix the other.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

Third Party AdvisoryTechnical DescriptionMitigation
Source: cverecord
https://www.hckrt.com/hacktivity/HCKRT-WM3VSE
Product
Source: cverecord
https://github.com/craftcms/cms

CVSS

8.8HIGHHackrate
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-94

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