# CVE-2026-115935: Control panel only API response emulation replaces "securityKey" and reaches server RCE

Status: published. Published: 2026-10-23. Updated: 2026-11-02.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- craftcms / cms (craftcms/cms): ≥ 5.0.0; < 5.11.2 (affected, semver); ≥ 4.0.0; < 4.18.9 (affected, semver). Source: CNA: Hackrate

## Severity and prioritization

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: Hackrate

- CVSS 3.1: 8.8 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H; source: CNA: Hackrate

- CISA KEV: No listing in collected sources

- EPSS: 0.37% as of 2026-11-02; percentile 30.80%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-94

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://www.hckrt.com/hacktivity/HCKRT-WM3VSE (CNA: Hackrate; third-party-advisory, technical-description, mitigation)

- https://github.com/craftcms/cms/releases/tag/5.11.2 (CNA: Hackrate; release-notes)

- https://github.com/craftcms/cms (CNA: Hackrate; product)

- https://github.com/craftcms/cms/security/advisories/GHSA-9hp6-3565-gvh5 (CNA: Hackrate; third-party-advisory)

## Provenance

- CNA: Hackrate: https://www.cve.org/CVERecord?id=CVE-2026-115935; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-115935; retrieved 2026-11-02; source updated Not reported

Revision: 840fa5d448f5c1c6d2681d79ba46785265ce1b04e82582389a0f69d57bb59fb9

Canonical: https://y2.dev/cve/CVE-2026-115935

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.