Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Search

GHSA-mqcf-gqvg-rmhm

LowCVSS 2.3 / 10
Published May 21, 2026·Last modified May 21, 2026
Affected Components(0)

No affected components available

Description

Impact

Users are impacted if:

  • They have a caveat structure with a nested list, e.g.:
  caveat shape(x list<any>) {
    x == [["a"], "b"]
  }
  • Their system exercises that caveat with either CheckBulkPermission or else LookupResources running with the --experimental-lookup-resources-version flag set to lr3, implying they are using the experimental version 3 of LookupResources
  • An attacker can cause the system to craft a request to SpiceDB where either:
    1. It's a CheckBulk request where there are two check items that are identical except for their combined caveat context, and one of the caveat contexts evaluates positively and the other evaluates negatively
    2. It's a LookupResources request where two resources have the same evaluation contents except for their caveat context, and one would evaluate positively and the other would evaluate negatively

If all of the above are true, it would be possible for SpiceDB to erroneously return that a user has access to a resource that they do not have access to.

Patches

This problem was addressed in https://github.com/authzed/spicedb/pull/3065 and released in version v1.52.0.

Workarounds

If using v3 of LookupResources, turn the flag off.

If possible, refactor the caveat declaration structure so that it does not operate on a list of lists, but rather any other composite structure.

Risk Scores
Base Score
2.3

The vulnerability can be exploited over the network without needing physical access. It is difficult for an attacker to exploit this vulnerability and may require special conditions. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
0.6

Limited exploitation activity has been observed. Close monitoring and planned remediation are recommended.

EPSS
0.28%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard