Vulnerability-Lookup

CVE-2026-55670 (GCVE-0-2026-55670)

Vulnerability from cvelistv5 – Published: 2026-07-10 17:15 – Updated: 2026-07-10 20:58

Title

ZITADEL: Cross-Tenant User Leakage via Recycled Identifiers

Summary

ZITADEL is an open source identity management platform. Prior to 4.15.1, ZITADEL's event store validation can retain the original resource owner for a deleted user identifier, causing a later user recreated with the same identifier in another organization to be provisioned under the original organization and exposed to that organization's administrator. This issue is fixed in version 4.15.2.

Severity

2.3 (Low)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-284 - Improper Access Control
CWE-639 - Authorization Bypass Through User-Controlled Key

Assigner

GitHub_M

References

4 references

URL	Tags
https://github.com/zitadel/zitadel/security/advis…	x_refsource_CONFIRM
https://github.com/zitadel/zitadel/pull/12261	x_refsource_MISC
https://github.com/zitadel/zitadel/commit/a939b84…	x_refsource_MISC
https://github.com/zitadel/zitadel/releases/tag/v4.15.2	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
zitadel	zitadel	Affected: < 4.15.2

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-55670

Vulnerability from fkie_nvd - Published: 2026-07-10 18:16 - Updated: 2026-07-10 21:16

Severity

2.3 (Low) - CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/zitadel/zitadel/commit/a939b847d90c3370bd162064e57764b89c01be46
	security-advisories@github.com	https://github.com/zitadel/zitadel/pull/12261
	security-advisories@github.com	https://github.com/zitadel/zitadel/releases/tag/v4.15.2
	security-advisories@github.com	https://github.com/zitadel/zitadel/security/advisories/GHSA-6x8v-2fq5-2229

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "zitadel",
          "vendor": "zitadel",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 4.15.2"
            }
          ]
        }
      ],
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    }
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  "cveTags": [],
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    {
      "lang": "en",
      "value": "ZITADEL is an open source identity management platform. Prior to 4.15.1, ZITADEL\u0027s event store validation can retain the original resource owner for a deleted user identifier, causing a later user recreated with the same identifier in another organization to be provisioned under the original organization and exposed to that organization\u0027s administrator. This issue is fixed in version 4.15.2."
    }
  ],
  "id": "CVE-2026-55670",
  "lastModified": "2026-07-10T21:16:56.973",
  "metrics": {
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GHSA-6X8V-2FQ5-2229

Vulnerability from github – Published: 2026-06-18 13:07 – Updated: 2026-06-18 13:07

Summary

ZITADEL: Cross-Tenant User Leakage via Recycled Identifiers

Details

Summary

A flaw in the user lifecycle enforcement allowed deleted users to retain their original organization/tenant association. Recreating a deleted user under a distinct organization can cause the new user instance to be incorrectly provisioned within the original organization if the previous ID would be used to recreate it.

Impact

When a user is created, the system maps the generated or provided ID to its target organization (Org A). When that user is subsequently deleted, a deletion event is appended to the stream, but the historical mapping of the resource owner within the event store's validation layer is not cleared.

If a new user is later provisioned in a different organization (Org B) using that exact same ID, the event store validation logic reads the stream's history, matches it to the original organization, and routes the new user's events to Org A instead of Org B.

This issue represents a localized multi-tenancy isolation anomaly rather than an easily exploitable attack vector. Because the new user instance is incorrectly routed and provisioned inside Org A instead of Org B, an administrator from Org A inadvertently gains full access to this new user record.

However, there is no technical mechanism for a malicious actor to force, automate, or target this behavior against a specific user or tenant. Because the scenario relies entirely on an accidental sequence of operational events and requires the recycling of a highly specific ID space, the practical security risk is exceptionally low.

Affected Versions

Systems running one of the following versions are affected:

4.x: 4.0.0 through 4.15.1 (including RC versions)
3.x: 3.0.0 through 3.4.11 (including RC versions)

Patches

The vulnerability has been addressed in the latest releases. The patch resolves the issue by requiring the correct permission in case the verification flag is provided and only allows self-management of the email address, resp. phone number itself.

4.x: Upgrade to $\ge$4.15.2
3.x: Update to $\ge$4.15.2

Workarounds

The recommended solution is to upgrade to a patched version.

Questions

If you have any questions or comments about this advisory, please email us at security@zitadel.com

Credits

Thanks to Charlie Graven from Famedly for reporting this vulnerability.

Severity

2.3 (Low)


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

Show details on source website

JSON

To clipboard

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  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/zitadel/zitadel"
      },
      "ranges": [
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          "events": [
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              "introduced": "0"
            },
            {
              "fixed": "1.80.0-v2.20.0.20260615092437-6082e59d47c1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55670"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-284",
      "CWE-639"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-18T13:07:34Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "### Summary\n\nA flaw in the user lifecycle enforcement allowed deleted users to retain their original organization/tenant association. Recreating a deleted user under a distinct organization can cause the new user instance to be incorrectly provisioned within the original organization if the previous ID would be used to recreate it.\n\n### Impact\n\nWhen a user is created, the system maps the generated or provided ID to its target organization (`Org A`). When that user is subsequently deleted, a deletion event is appended to the stream, but the historical mapping of the resource owner within the event store\u0027s validation layer is not cleared.\n\nIf a new user is later provisioned in a different organization (`Org B`) using that exact same ID, the event store validation logic reads the stream\u0027s history, matches it to the original organization, and routes the new user\u0027s events to `Org A` instead of `Org B`.\n\nThis issue represents a localized multi-tenancy isolation anomaly rather than an easily exploitable attack vector. Because the new user instance is incorrectly routed and provisioned inside `Org A` instead of `Org B`, an administrator from `Org A` inadvertently gains full access to this new user record.\n\nHowever, there is no technical mechanism for a malicious actor to force, automate, or target this behavior against a specific user or tenant. Because the scenario relies entirely on an accidental sequence of operational events and requires the recycling of a highly specific ID space, the practical security risk is exceptionally low.\n\n### Affected Versions\n\nSystems running one of the following versions are affected:\n\n* **4.x:** `4.0.0` through `4.15.1` (including RC versions)\n* **3.x:** `3.0.0` through `3.4.11` (including RC versions)\n\n### Patches\n\nThe vulnerability has been addressed in the latest releases. The patch resolves the issue by requiring the correct permission in case the verification flag is provided and only allows self-management of the email address, resp. phone number itself.\n\n- **4.x**: Upgrade to $\\ge$[4.15.2](https://github.com/zitadel/zitadel/releases/tag/v4.15.2)\n- **3.x**: Update to $\\ge$[4.15.2](https://github.com/zitadel/zitadel/releases/tag/v4.15.2)\n\n### Workarounds\n\nThe recommended solution is to upgrade to a patched version. \n\n### Questions\n\nIf you have any questions or comments about this advisory, please email us at [security@zitadel.com](mailto:security@zitadel.com)\n\n### Credits\n\nThanks to Charlie Graven from Famedly for reporting this vulnerability.",
  "id": "GHSA-6x8v-2fq5-2229",
  "modified": "2026-06-18T13:07:35Z",
  "published": "2026-06-18T13:07:34Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/zitadel/zitadel/security/advisories/GHSA-6x8v-2fq5-2229"
    },
    {
      "type": "WEB",
      "url": "https://github.com/zitadel/zitadel/commit/6082e59d47c17a9d54a6b0556b3f31559d7c620a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/zitadel/zitadel"
    },
    {
      "type": "WEB",
      "url": "https://github.com/zitadel/zitadel/releases/tag/v4.15.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": " ZITADEL: Cross-Tenant User Leakage via Recycled Identifiers"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-55670 (GCVE-0-2026-55670)

FKIE_CVE-2026-55670

GHSA-6X8V-2FQ5-2229

Summary

Impact

Affected Versions

Patches

Workarounds

Questions

Credits

Tags

Sightings

Nomenclature