@hono/oauth-providers is Authentication middleware for Hono. Prior to version 0.8.6, the built-in social login providers accept an OAuth callback even when the `state` value is absent on both sides, so the anti-CSRF check passes for a callback that never came from a genuine login attempt. This defeats the `state`-based CSRF protection under default usage. Version 0.8.6 has a patch.
@hono/oauth-providers is Authentication middleware for Hono. Prior to version 0.8.6, the built-in social login providers accept an OAuth callback even when the `state` value is absent on both sides, so the anti-CSRF check passes for a callback that never came from a genuine login attempt. This defeats the `state`-based CSRF protection under default usage. Version 0.8.6 has a patch.
@hono/oauth-providers is Authentication middleware for Hono. Prior to version 0.8.6, the built-in social login providers accept an OAuth callback even when the `state` value is absent on both sides, so the anti-CSRF check passes for a callback that never came from a genuine login attempt. This defeats the `state`-based CSRF protection under default usage. Version 0.8.6 has a patch.
### Summary
The built-in social login providers accept an OAuth callback even when the `state` value is absent on both sides, so the anti-CSRF check passes for a callback that never came from a genuine login attempt. This defeats the `state`-based CSRF protection under default usage.
### Details
The `state` check treated two absent values as a match, so a callback that omits `state` — and for which no `state` was ever stored — was allowed to redeem the authorization code. Hono's `csrf()` middleware does not help: it only inspects form-style requests, while the OAuth callback is a top-level `GET` navigation it treats as safe.
This affects the `google`, `github`, `facebook`, `discord`, `twitch`, `linkedin`, and `msentra` providers. The `x` (Twitter) provider is not exploitable due to its PKCE binding.
### Impact
An attacker can make a victim's browser complete an OAuth callback that binds the attacker's identity instead of the victim's, leading to login CSRF (the victim silently acts inside the attacker's account) or forced account linking (the attacker's identity is linked to the victim's account, enabling later sign-in as the victim). Affects applications using an affected provider on `@hono/oauth-providers` `0.8.5` or earlier.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Aug 31, 2026, 8:27:33 PM
dateUpdated: Sep 1, 2026, 2:59:01 PM
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Deferred
Weakness classifications: CWE-352 · CWE-1275
Original publisher date fields
published: 2026-08-31T21:17:52.317
lastModified: 2026-09-09T21:09:13.080
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.