High severity · published Jul 10, 2026
CVE-2026-56668
ZITADEL: Unauthorized Token Privilege Escalation in OAuth2 Token Exchange
8.1
CVSS
0.4%
EPSS
No
On KEV
Description
ZITADEL is an open source identity management platform. Prior to 4.15.3, ZITADEL's OAuth2 Token Exchange endpoint for urn:ietf:params:oauth:grant-type:token-exchange does not verify that the subject token belongs to the requesting client or that requested scopes remain within the original token's scopes, allowing a low-privilege token to be exchanged for elevated permissions at another application. This issue is fixed in version 4.15.3.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZI
zitadel · zitadel
< 4.15.3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56668
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-56668
github.com
https://github.com/zitadel/zitadel/commit/e2886a61670ca8fd41c9434f87036546e5620bcc
github.com
https://github.com/zitadel/zitadel/releases/tag/v4.15.3
github.com
https://github.com/zitadel/zitadel/security/advisories/GHSA-vrh8-c9cm-wh8v
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