CVE-2022-21721

DOS Vulnerability in next.js

HIGH
7.5
CVSS Score
Published: January 28, 2022 at 10:00 PM UTC
Updated: June 17, 2026 at 04:26 AM UTC
1 product affected across 1 vendorNext.js

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Severity
HIGH7.5
Exploit prediction
EPSS 2%
SSVC
No known exploit

Description

Next.js is a React framework. Starting with version 12.0.0 and prior to version 12.0.9, vulnerable code could allow a bad actor to trigger a denial of service attack for anyone using i18n functionality. In order to be affected by this CVE, one must use next start or a custom server and the built-in i18n support. Deployments on Vercel, along with similar environments where invalid requests are filtered before reaching Next.js, are not affected. A patch has been released, `[email protected]`, that mitigates this issue. As a workaround, one may ensure `/${locale}/_next/` is blocked from reaching the Next.js instance until it becomes feasible to upgrade.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

12.0.0 ≤ v < 12.0.9
Affected range stops below 12.0.9, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_MISCPatchThird Party Advisory
https://github.com/vercel/next.js/pull/33503
x_refsource_MISCRelease NotesThird Party Advisory
https://github.com/vercel/next.js/releases/tag/v12.0.9

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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