Summary
Strawberry GraphQL: Synchronous permission checks can treat an awaitable authorization result as truthy
PermissionExtension.resolve() evaluates the return value of has_permission() for truthiness on the synchronous path. supports_sync only classifies a permission as asynchronous when has_permission is declared with async def (via inspect.iscoroutinefunction), so a plain def that returns an awaitable is treated as synchronous. An awaitable is always truthy, so the check passes even when it resolves to False and the protected resolver runs.
The resolve path is chosen by the field resolver, not by the execution method, so any field with a synchronous resolver is affected under both execute_sync() and execute(). Permissions declared with async def has_permission(), or a plain def returning a boolean, are not affected.
Details
The affected code is PermissionExtension.resolve() in strawberry/permission.py. A permission attached to a field whose has_permission is a normal def returning an awaitable reaches this path; the awaitable is never awaited and its truthiness grants access. resolve_async() is not affected because it uses await_maybe().
PoC
import strawberry
from strawberry.permission import BasePermission
class DenyViaAwaitable(BasePermission):
message = "denied"
def has_permission(self, source, info, **kwargs):
async def result():
return False
return result()
@strawberry.type
class Query:
@strawberry.field(permission_classes=[DenyViaAwaitable])
def secret(self) -> str:
return "secret"
schema = strawberry.Schema(Query)
print(schema.execute_sync("{ secret }").data) # {'secret': 'secret'} instead of a permission error
Impact
An application using a custom permission whose has_permission is a normal def returning an awaitable can unintentionally grant access to the protected field. Standard permissions (a def returning a boolean, or an async def) are not affected, so exploitability depends on the application using this specific permission shape.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
CVE-2026-107728 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.326.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The synchronous path now fails closed: if has_permission() returns an awaitable, an error is raised instead of granting access.
Frequently Asked Questions
- What is CVE-2026-107728? CVE-2026-107728 is a high-severity incorrect authorization vulnerability in strawberry-graphql (pip), affecting versions >= 0.217.0, <= 0.326.0. It is fixed in 0.326.1. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- How severe is CVE-2026-107728? CVE-2026-107728 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of strawberry-graphql are affected by CVE-2026-107728? strawberry-graphql (pip) versions >= 0.217.0, <= 0.326.0 is affected.
- Is there a fix for CVE-2026-107728? Yes. CVE-2026-107728 is fixed in 0.326.1. Upgrade to this version or later.
- Is CVE-2026-107728 exploitable, and should I be worried? Whether CVE-2026-107728 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-107728 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-107728? Upgrade
strawberry-graphqlto 0.326.1 or later.