# CVE-2026-119127: ZITADEL 4.0.0 before 4.19.5 Account Takeover via Login V2 Host Header Injection

Status: published. Published: 2026-10-29. Updated: 2026-11-04.

ZITADEL 4.0.0 before 4.19.5 contains a host header injection vulnerability in the Login V2 UI that allows unauthenticated attackers to poison password-reset, invite, and email-verification links by supplying untrusted x-zitadel-public-host, x-zitadel-forward-host, or x-forwarded-host headers. Attackers knowing a victim's login name can point the links in genuine emails at their host, harvest the single-use codes when the links are opened, and take over accounts including instance administrators.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- zitadel / zitadel: ≥ 4.0.0; < 4.19.5 (affected, semver); 4.19.5 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.6 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 8.1 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.28% as of 2026-11-03; percentile 20.30%

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

- Weaknesses: CWE-640

## Exploit evidence

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

## References

- https://github.com/zitadel/zitadel/security/advisories/GHSA-mchc-246r-6m76 (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/zitadel-4.0.0-before-4.19.5-account-takeover-via-login-v2-host-header-injection (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-119127; retrieved 2026-11-04; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-119127; retrieved 2026-11-04; source updated Not reported

Revision: 2c2c8155168188ae65aa54e4e6c88a107173e1dc07ded484a72a20136a378e33

Canonical: https://y2.dev/cve/CVE-2026-119127

## 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, filters, sort, 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.