CVE-2026-109373

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

HIGH
8.1
CVSS Score
Published: October 12, 2026 at 04:05 PM UTC
Updated: October 13, 2026 at 05:17 PM UTC
1 product affected across 1 vendorZitadel

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Severity
HIGH8.1
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 4.19.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-441

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