Forced account linking via missing OAuth state
Published Aug 31, 2026 · Updated Sep 1, 2026
Cross-site request forgery in Hono @hono/oauth-providers before 0.8.6 allows remote attackers to force OAuth account linking. The callback handler compares the query and cookie state values without first requiring either one, so two absent values match and authorization-code redemption continues. Exploitation requires a victim to follow an attacker-initiated callback, after which the attacker's identity is linked to the victim's account or the victim acts in the attacker's account.
Summary
What happened
Cross-site request forgery in Hono @hono/oauth-providers before 0.8.6 allows remote attackers to force OAuth account linking. The callback handler compares the query and cookie state values without first requiring either one, so two absent values match and authorization-code redemption continues. Exploitation requires a victim to follow an attacker-initiated callback, after which the attacker's identity is linked to the victim's account or the victim acts in the attacker's account.
The record
- CVE
- CVE-2026-81888
- Published
- Aug 31, 2026
- Updated
- Sep 1, 2026
- Vendor
- Hono
- Product
- @hono/oauth-providers
- Classifications
- CWE-352, CWE-1275, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 31, 2026CVE publishedPublication date reported by the CVE source.
- Sep 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.8.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo