CVE-2026-110008: @fastify/oauth2 · Cross-Site Request Forgery (CSRF)
Affects @fastify/oauth2Source CVE Database V5
Not known to be exploited · CVSS 4.2 Medium : upgrade to 8.3.2 when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.09% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-10-19.
- Patch
- Available – fixed in 8.3.2
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 19 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade @fastify/oauth2 to 8.3.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| @fastify/oauth2@fastify/oauth2 | Affected
| Fixed in
|
npm@fastify/oauth2pkg:npm/@fastify/oauth2Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade @fastify/oauth2 to version 8.3.2 or later, where the issue is fixed. As a temporary workaround, explicitly set the cookie Path attribute so that the cookies set and cleared share the same path, ensuring the single-use guarantee of the state cookie is enforced.
Description
@fastify/oauth2 versions 7.2.0 through 8.3.1 contain a Cross-Site Request Forgery (CSRF) vulnerability due to inconsistent cookie Path attributes for state and code-verifier cookies during OAuth2 login flows. This inconsistency allows the state cookie to persist beyond the OAuth callback, violating the single-use guarantee. An attacker who learns a valid state value can perform login CSRF by forcing the victim's browser to sign into the attacker’s account. The issue is fixed in version 8.3.2.