CVE-2021-21310 | Token verification bug in next-auth

Exp

NextAuth.js (next-auth) is am open source authentication solution for Next.js applications. In next-auth before version 3.3.0 there is a token verification vulnerability. Implementations using the Prisma database adapter in conjunction with the Email provider are impacted. Implementations using the Email provider with the default database adapter are not impacted. Implementations using the Prisma database adapter but not using the Email provider are not impacted. The Prisma database adapter was checking the verification token, but was not verifying the email address associated with that token. This made it possible to use a valid token to sign in as another user when using the Prima adapter in conjunction with the Email provider. This issue is specific to the community supported Prisma adapter. This issue is fixed in version 3.3.0.

Published: 2021-02-11 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-21310 is rated Exploit Available (59.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.37%). 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-2021-21310

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

Exploit prediction scoring system (EPSS) score for CVE-2021-21310

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 2025-11-21 0.30% 0.37% +0.07%
2 2025-11-18 0.37% 0.30% -0.07%
3 2025-07-25 — 0.37% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-21310

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.6 4.0 [email protected]
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-21310

GitHub Security Advisory for CVE-2021-21310

GHSA-pg53-56cg-4m8q · Severity: low · Ecosystem: npm — Token verification bug in next-auth

Affected software / configurations for CVE-2021-21310

Vendor Product Version Raw CPE
nextauth.js next-auth < 3.3.0 cpe:2.3:a:nextauth.js:next-auth:*:*:*:*:*:node.js:*:*

References for CVE-2021-21310

cvelogic Threat Intelligence