Dex: Token-exchange endpoint is missing AllowedConnectors enforcement

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.7 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary server/handlers.go::handleTokenExchange (lines 1804-1893) does not call isConnectorAllowed(client.AllowedConnectors, connID) before issuing tokens, while sibling handlers do. This is a per-client connector ACL gap on the token-exchange endpoint; the redirect-flow paths enforce the same field correctly. Affected code path handleTokenExchange reads connectorid from the request body at server/handlers.go:1822. Validators called between read and token issuance: - s.getConnector(ctx, connID) at line 1836 - confirms connector exists - GrantTypeAllowed(conn.GrantTypes, grantTypeTokenExchange) at line 1842 - confirms connector permits this grant - (missing) isConnectorAllowed(client.AllowedConnectors, connID) - never called Tokens are issued at lines 1887 / 1889, bound to client.ID carrying claims derived from connID. Sibling handlers DO enforce the check: - server/handlers.go::handleConnectorLogin:377 - calls isConnectorAllowed, returns HTTP 403 "Connector not allowed for this…

Published by the source

9 Jun 2026, 21:59 UTC

Last modified by the source

9 Jun 2026, 21:59 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-7qjx-gp9h-65qj

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# Patch Next advisory brief: GHSA-7qjx-gp9h-65qj

Advisory: Dex: Token-exchange endpoint is missing AllowedConnectors enforcement
IDs: GHSA-7qjx-gp9h-65qj
Record: https://patchnext.com/advisories/ghsa-7qjx-gp9h-65qj (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/dexidp/dex 0.0.0-20260303131938-204dbb2e3ff7. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/dexidp/dex: affected < 0.0.0-20260303131938-204dbb2e3ff7; fixed in 0.0.0-20260303131938-204dbb2e3ff7

## Suggested inspection (read-only)
- Go github.com/dexidp/dex: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/dexidp/dex.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-7qjx-gp9h-65qj (GitHub-reviewed advisory GHSA-7qjx-gp9h-65qj lists affected ranges: Go github.com/dexidp/dex >=0 <0.0.0-20260303131938-204dbb2e3ff7)

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