CVE-2026-109373 PUBLISHED

ZITADEL 3.0.0 before 4.19.2 Account Takeover via Unsigned Login V2 Session Cookie

Assigner: VulnCheck
Reserved: 12.10.2026 Published: 12.10.2026 Updated: 12.10.2026

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.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 9.2

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 8.1

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	zitadel
Product	zitadel
Versions	Default: unaffected affected from 3.0.0 to 4.19.2 (excl.) Version 4.19.2 is unaffected

CVE-2026-109373 PUBLISHED

ZITADEL 3.0.0 before 4.19.2 Account Takeover via Unsigned Login V2 Session Cookie

Metrics

Product Status

Credits

References

Problem Types