Vulnerability · Published Jul 10, 2026 · Assigned by GitHub_M

CVE-2026-56668ZITADEL: Unauthorized Token Privilege Escalation in OAuth2 Token Exchange

High 8.1

In plain English

A high-severity missing authorization 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 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.4%top 64.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/zitadel/zitadel	4.15.3	GHSA-vrh8-c9cm-wh8v
Go	github.com/zitadel/zitadel	no fix listed	GO-2026-6474

Affected products (as reported)

Vendor	Product	Versions
zitadel	zitadel	< 4.15.3

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References

https://github.com/zitadel/zitadel/security/advisories/GHSA-vrh8-c9cm-wh8v x_refsource_CONFIRM
https://github.com/zitadel/zitadel/commit/e2886a61670ca8fd41c9434f87036546e5620bcc x_refsource_MISC
https://github.com/zitadel/zitadel/releases/tag/v4.15.3 x_refsource_MISC