Vulnerability · Published Oct 12, 2026 · Assigned by VulnCheck

CVE-2026-109373ZITADEL 3.0.0 before 4.19.2 Account Takeover via Unsigned Login V2 Session Cookie

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 0.4% (higher than 37% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.4%top 63.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

ZITADEL 3.0.0 before 4.19.2 contains an authentication bypass vulnerability in the Login V2 UI that allows unauthenticated attackers to obtain other users' session tokens by forging unsigned session cookies. Attackers can guess time-ordered session IDs around a victim's sign-in and supply them with empty tokens to receive rotated tokens, taking over accounts including MFA-completed administrator sessions.

Affected products (as reported)

Vendor	Product	Versions
zitadel	zitadel	3.0.0 – before 4.19.2

Weakness: CWE-441 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

GitHub Security Advisory (GHSA-jh92-5mrj-p2w2) vendor-advisory
VulnCheck Advisory: ZITADEL 3.0.0 before 4.19.2 Account Takeover via Unsigned Login V2 Session Cookie third-party-advisory