CVE-2023-31999

Exp

All versions of @fastify/oauth2 used a statically generated state parameter at startup time and were used across all requests for all users. The purpose of the Oauth2 state parameter is to prevent Cross-Site-Request-Forgery attacks. As such, it should be unique per user and should be connected to the user's session in some way that will allow the server to validate it. v7.2.0 changes the default behavior to store the state in a cookie with the http-only and same-site=lax attributes set. The state is now by default generated for every user. Note that this contains a breaking change in the checkStateFunction function, which now accepts the full Request object.

Published: 2023-07-04 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-31999 is rated High Exploit Risk (78.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.31%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-31999

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-31999

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-29 1.15% 1.31% +0.16%
2 2026-03-04 0.44% 1.15% +0.71%
3 2026-03-01 — 0.44% —

Full EPSS history (45 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-31999

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]

Weakness enumeration for CVE-2023-31999

GitHub Security Advisory for CVE-2023-31999

GHSA-g8x5-p9qc-cf95 · Severity: high · Ecosystem: npm — @fastify/oauth2 vulnerable to Cross Site Request Forgery due to reused Oauth2 state

OS Trackers for CVE-2023-31999

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2023-31999

Affected software / configurations for CVE-2023-31999

Vendor Product Version Raw CPE
fastify oauth2 < 7.2.0 cpe:2.3:a:fastify:oauth2:*:*:*:*:*:*:*:*

References for CVE-2023-31999

cvelogic Threat Intelligence