Answer in brief
CVE-2026-110008 records a Medium severity (CVSS 4.2) vulnerability in @fastify/oauth2 vulnerable to Login CSRF via OAuth state cookie not cleared after callback. The current sources do not mark it as known exploited. The current feed maps @fastify/oauth2/@fastify/oauth2 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 4.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps @fastify/oauth2/@fastify/oauth2 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| @fastify/oauth2/@fastify/oauth2generic | >=7.2.0 <8.3.2 | 8.3.2 |
Published upstream
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 19, 2026
@fastify/oauth2 is a Fastify wrapper for OAuth2 login flows. In versions 7.2.0 through 8.3.1, the state and code-verifier cookies are set without a Path attribute at a login route with two or more path segments, while the clearing step at the OAuth callback writes them with a root path, so the original cookies survive the callback and the documented single-use guarantee for the state value does not hold. A state value an attacker learns stays valid for the rest of the browser session, letting the attacker drive their own authorization flow in the victim's browser and sign the victim in to the attacker's account (login CSRF). The issue is fixed in @fastify/oauth2 8.3.2, and users should upgrade to 8.3.2 or later. As a workaround, set an explicit cookie path so the set and the clear name the same cookie.
Quoted source text, attributed separately from HOL analysis.