@hono/oauth-providers: OAuth state check fails open on omitted state, enabling login CSRF and forced account linking — GHSA-FM3F-CH8H-QW8Q

Summary

### 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…

Timeline

Published by source

2026-08-31

Risk context

• Reported severity or threat level: medium.
• Reported CVSS score: 5.4 out of 10.
• Review exposure for the affected product or family: npm: @hono/oauth-providers.

Product

npm: @hono/oauth-providers

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-FM3F-CH8H-QW8Q

Source

GitHub

Vendor

GitHub

Published by source

2026-08-31

Last source activity

2026-08-31

Additional identifiers

CVE-2026-81888

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.