Vulnerability-Lookup

CVE-2026-55866 (GCVE-0-2026-55866)

Vulnerability from cvelistv5 – Published: 2026-09-14 17:23 – Updated: 2026-09-14 18:15

Title

SpiceDBChecks involving relations with caveats can result in unconditional permission when conditional permission is expected

Summary

SpiceDB is an open source database system for creating and managing security-critical application permissions. From 1.34.0 until 1.54.0, SpiceDB can return PERMISSIONSHIP_HAS_PERMISSION instead of PERMISSIONSHIP_CONDITIONAL_PERMISSION or PERMISSIONSHIP_NO_PERMISSION because checkRequestToKey() and checkRequestToKeyWithCanonical() in internal/dispatch/keys/computed.go omit CheckHints when constructing dispatch Check cache keys. The incorrect result requires a permission combining relations with intersection or exclusion, a subject reachable through caveated and non-caveated branches, LookupResources with a context parameter running concurrently with CheckPermission or CheckBulkPermissions for the same resource and subject, and an enabled dispatch result cache. Under these conditions, a result computed for one hint set can poison the cache entry used by a semantically different authorization check, allowing permission without satisfying the caveat. This issue is fixed in version 1.54.0.

Severity

3.7 (Low)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-14 18:15 UTC

CWE

CWE-863 - Incorrect Authorization

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/authzed/spicedb/security/advis…	x_refsource_CONFIRM
https://github.com/authzed/spicedb/pull/3188	x_refsource_MISC
https://github.com/authzed/spicedb/commit/44a1c9f…	x_refsource_MISC
https://github.com/authzed/spicedb/commit/ccde792…	x_refsource_MISC
https://github.com/authzed/spicedb/releases/tag/v1.54.0	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
authzed	spicedb	Affected: >= 1.34.1, < 1.54.0	guessed

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-55866",
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FKIE_CVE-2026-55866

Vulnerability from fkie_nvd - Published: 2026-09-14 18:17 - Updated: 2026-09-14 19:17

Severity

3.7 (Low) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/authzed/spicedb/commit/44a1c9f266bd8a884bfebfc27181210302541b9b
	security-advisories@github.com	https://github.com/authzed/spicedb/commit/ccde792fc48750740d025d4286d5c2c88614cd30
	security-advisories@github.com	https://github.com/authzed/spicedb/pull/3188
	security-advisories@github.com	https://github.com/authzed/spicedb/releases/tag/v1.54.0
	security-advisories@github.com	https://github.com/authzed/spicedb/security/advisories/GHSA-4vrg-r928-h5vv

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "spicedb",
          "vendor": "authzed",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.34.1, \u003c 1.54.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "SpiceDB is an open source database system for creating and managing security-critical application permissions. From 1.34.0 until 1.54.0, SpiceDB can return PERMISSIONSHIP_HAS_PERMISSION instead of PERMISSIONSHIP_CONDITIONAL_PERMISSION or PERMISSIONSHIP_NO_PERMISSION because checkRequestToKey() and checkRequestToKeyWithCanonical() in internal/dispatch/keys/computed.go omit CheckHints when constructing dispatch Check cache keys. The incorrect result requires a permission combining relations with intersection or exclusion, a subject reachable through caveated and non-caveated branches, LookupResources with a context parameter running concurrently with CheckPermission or CheckBulkPermissions for the same resource and subject, and an enabled dispatch result cache. Under these conditions, a result computed for one hint set can poison the cache entry used by a semantically different authorization check, allowing permission without satisfying the caveat. This issue is fixed in version 1.54.0."
    }
  ],
  "id": "CVE-2026-55866",
  "lastModified": "2026-09-14T19:17:33.193",
  "metrics": {
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          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
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    },
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GHSA-4VRG-R928-H5VV

Vulnerability from github – Published: 2026-06-19 21:42 – Updated: 2026-06-19 21:42

Summary

SpiceDB: Checks involving relations with caveats can result in unconditional permission when conditional permission is expected

Details

Impact

Under concurrency, CheckPermission and CheckBulkPermissions can return PERMISSIONSHIP_HAS_PERMISSION for a (resource, permission, subject) whose correct answer is PERMISSIONSHIP_CONDITIONAL_PERMISSION.

You are impacted if all of the following hold:

Your schema has a permission combining relations with an intersection or exclusion, where a subject reaches it through a caveated branch and a non-caveated branch. For example:

  definition user {}

  caveat some_caveat(somecondition int) { somecondition == 42 }

  definition document {
    relation reader: user | user with some_caveat
    relation writer: user
    relation banned: user
    permission has_permission = (reader & writer) - banned
  }

A subject reaches the permission via the caveated edge:

  document:firstdoc#reader@user:caveatedreader[some_caveat]
  document:firstdoc#writer@user:caveatedreader

Your workload issues LookupResources with a context request parameter, concurrently with CheckPermission/CheckBulkPermissions for the same subject/resource, and
The dispatch result cache is enabled.

When all of the above are true, there is an intermittent window in which:

CheckPermission(document:firstdoc, has_permission, user:caveatedreader) → HAS_PERMISSION (incorrect; should be CONDITIONAL_PERMISSION)

CheckPermission(document:firstdoc, has_permission, user:caveatedreader, context = {"somecondition": 41}) → HAS_PERMISSION (incorrect; should be NO_PERMISSION)

Patches

v1.54.0

Workarounds

Disable the dispatch result cache (ClusterDispatchCacheConfig and DispatchCacheConfig)

Severity

3.7 (Low)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/authzed/spicedb"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.34.0"
            },
            {
              "fixed": "1.54.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55866"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-19T21:42:12Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "### Impact\n Under concurrency, `CheckPermission` and `CheckBulkPermissions` can return `PERMISSIONSHIP_HAS_PERMISSION` for a (resource, permission, subject) whose correct answer is   `PERMISSIONSHIP_CONDITIONAL_PERMISSION`. \n\n You are impacted if **all** of the following hold:\n\n  1. Your schema has a permission combining relations with an intersection or exclusion, where a subject reaches it through a caveated branch and a non-caveated branch. For example:\n\n```zed\n  definition user {}\n\n  caveat some_caveat(somecondition int) { somecondition == 42 }\n\n  definition document {\n    relation reader: user | user with some_caveat\n    relation writer: user\n    relation banned: user\n    permission has_permission = (reader \u0026 writer) - banned\n  }\n```\n\n  2. A subject reaches the permission via the caveated edge:\n\n```\n  document:firstdoc#reader@user:caveatedreader[some_caveat]\n  document:firstdoc#writer@user:caveatedreader\n```\n  3. Your workload issues `LookupResources` with a `context` request parameter, concurrently with `CheckPermission/CheckBulkPermissions` for the same subject/resource, and\n  4. The dispatch result cache is enabled.\n  \nWhen all of the above are true, there is an intermittent window in which:\n\n`CheckPermission(document:firstdoc, has_permission, user:caveatedreader)` \u2192 HAS_PERMISSION (incorrect; should be CONDITIONAL_PERMISSION)\n\n`CheckPermission(document:firstdoc, has_permission, user:caveatedreader, context = {\"somecondition\": 41})` \u2192 HAS_PERMISSION (incorrect; should be NO_PERMISSION)\n\n### Patches\n\nv1.54.0\n\n### Workarounds\nDisable the dispatch result cache (`ClusterDispatchCacheConfig` and `DispatchCacheConfig`)",
  "id": "GHSA-4vrg-r928-h5vv",
  "modified": "2026-06-19T21:42:12Z",
  "published": "2026-06-19T21:42:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/authzed/spicedb/security/advisories/GHSA-4vrg-r928-h5vv"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/authzed/spicedb"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "SpiceDB: Checks involving relations with caveats can result in unconditional permission when conditional permission is expected"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

CVE-2026-55866 (GCVE-0-2026-55866)

FKIE_CVE-2026-55866

GHSA-4VRG-R928-H5VV

Impact

Patches

Workarounds

Tags

Sightings

Nomenclature