Vulnerability · Published Oct 29, 2026 · Assigned by VulnCheck

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

High 8.1

In plain English

A high-severity security flaw in zitadel from zitadel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.3%top 79.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
zitadel	zitadel	4.0.0 – before 4.19.5

Weakness: CWE-640 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

References

GitHub Security Advisory (GHSA-mchc-246r-6m76) vendor-advisory
VulnCheck Advisory: ZITADEL 4.0.0 before 4.19.5 Account Takeover via Login V2 Host Header Injection third-party-advisory