CVE-2026-55866

LOWPre-NVD 3.73.7
EchelonGraph scoreLOW confidence

This low-severity CVE scores 3.7 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:github_m
3.7
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 3.7Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

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)

CVSS v3
3.7
EG Score
3.7(low)
EPSS
—
KEV
Not listed

Published

June 19, 2026

Last Modified

June 19, 2026

Vendor Advisories for CVE-2026-55866(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/authzed/spicedb—1.54.0—

Data Freshness Timeline

(refreshed 3× in last 7d / 7× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-07 06:58 UTCEG score recompute
  2. 2026-07-04 09:27 UTCEG score recompute
  3. 2026-07-01 12:04 UTCEG score recompute
  4. 2026-06-28 14:41 UTCEG score recompute
  5. 2026-06-25 17:18 UTCEG score recompute
  6. 2026-06-22 19:55 UTCEG score recompute
  7. 2026-06-19 22:24 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-55866?
CVE-2026-55866 is a low vulnerability published on June 19, 2026. SpiceDB: Checks involving relations with caveats can result in unconditional permission when conditional permission is expected Impact Under concurrency, CheckPermission and CheckBulkPermissions can return PERMISSIONSHIPHASPERMISSION for a (resource, permission, subject) whose correct answer is…
When was CVE-2026-55866 disclosed?
CVE-2026-55866 was first published in the National Vulnerability Database on June 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-55866?
CVE-2026-55866 has a CVSS v4.0 base score of 3.7 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55866?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55866, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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