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GHSA-cf98-j28v-49v6 CVE-2026-55170 GO-2026-5322

OpenFGA Improper Policy Enforcement

Medium Go
Severity
0.0 / 10
Medium · CVSS 4.0
Exploit chance (EPSS)
0.34%
Chance of exploitation in the next 30 days. Higher than 27.36% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-178 Improper Handling of Case Sensitivity
Fix
1.18.0
Upgrade github.com/openfga/openfga to this version or later

Description

Description

In OpenFGA, when MySQL is being used as the datastore, two distinct check requests can return the same response.

Preconditions

This applies if the following preconditions are met:

  1. You run OpenFGA with MySQL as the datastore
  2. Your authorization decisions rely on case-sensitive user strings.

Fix

Upgrade to OpenFGA 1.18.0 or greater.

Acknowledgements

OpenFGA would like to thank @sahajamoth for the detailed report.

Affected versions

Go

PackageVulnerableFixed in
github.com/openfga/openfga
< 1.18.0
1.18.0

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/openfga/openfga Go → 1.18.0

go
go get github.com/openfga/openfga@v1.18.0 && go mod tidy

Severity breakdown

CVSS 4.0 0.0

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

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
Low
User interaction
Passive
Confidentiality (vulnerable system)
Low
Integrity (vulnerable system)
Low
Availability (vulnerable system)
None
Confidentiality (subsequent systems)
Low
Integrity (subsequent systems)
Low
Availability (subsequent systems)
None

CVSS 3.1 5.4

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

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

Weakness

CWE-178: Improper Handling of Case Sensitivity

The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.

How to prevent it
  • Architecture and Design: Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  • Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-g3pg-frfm-pr2m
OpenFGA: ListUsers returns a deliberately-excluded user when a `but not` exclusion under a type-bound wildcard is intersected (`and`) with another relation that also grants that user
Medium Also affects github.com/openfga/openfga
GHSA-hcxc-wf8j-23hv
OpenFGA: OIDC audience validation skipped when --authn-oidc-audience is unset
High Also affects github.com/openfga/openfga
GHSA-8396-jffm-qx4w
OpenFGA has cache-key delimiter injection in shared-iterator and v2 iterator that caches enables intra-store authorization-decision poisoning
Medium Also affects github.com/openfga/openfga
GHSA-57j5-qwp2-vqp6
OpenFGA has Improper Policy Enforcement
Medium Also affects github.com/openfga/openfga
GHSA-68m9-983m-f3v5
OpenFGA: Unauthenticated playground endpoint discloses preshared API key in HTML response
Medium Also affects github.com/openfga/openfga
GHSA-jwvj-g8pc-cx45
OpenFGA's BatchCheck within-request deduplication produces incorrect authorization decisions via list-value cache-key collision
High Also affects github.com/openfga/openfga
GHSA-h6c8-cww8-35hf
OpenFGA has an Authorization Bypass through cached keys
Critical Also affects github.com/openfga/openfga
GHSA-jq9f-gm9w-rwm9
OpenFGA Improper Policy Enforcement
High Also affects github.com/openfga/openfga
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