CVE-2021-37699
Open Redirect in Next.js versions below 11.1.0
Next.js is an open source website development framework to be used with the React library. In affected versions specially encoded paths could be used when pages/_error.js was statically generated allowing an open redirect to occur to an external site. In general, this redirect does not directly harm users although can allow for phishing attacks by redirecting to an attacker's domain from a trusted domain. We recommend everyone to upgrade regardless of whether you can reproduce the issue or not. The issue has been patched in release 11.1.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Open Redirect in Next.js versions below 11.1.0
Next.js is an open source website development framework to be used with the React library. In affected versions specially encoded paths could be used when pages/_error.js was statically generated allowing an open redirect to occur to an external site. In general, this redirect does not directly harm users although can allow for phishing attacks by redirecting to an attacker's domain from a trusted domain. We recommend everyone to upgrade regardless of whether you can reproduce the issue or not. The issue has been patched in release 11.1.0.
- Record
CVE-2021-37699- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
EUVDEUVD-2021-1904
Next.js is an open source website development framework to be used with the React library. In affected versions specially encoded paths could be used when pages/_error.js was statically generated allowing an open redirect to occur to an external site. In general, this redirect does not directly harm users although can allow for phishing attacks by redirecting to an attacker's domain from a trusted domain. We recommend everyone to upgrade regardless of whether you can reproduce the issue or not. The issue has been patched in release 11.1.0.
- Record
EUVD-2021-1904- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-vxf5-wxwp-m7g9
Open Redirect in Next.js
Next.js is an open source website development framework to be used with the React library. In affected versions specially encoded paths could be used when pages/_error.js was statically generated, allowing an open redirect to occur to an external site. In general, this redirect does not directly harm users although it can allow for phishing attacks by redirecting to an attacker's domain from a trusted domain.
Impact
- Affected: Users of Next.js between
10.0.5and10.2.0 - Affected: Users of Next.js between
11.0.0and11.0.1usingpages/_error.jswithoutgetInitialProps - Affected: Users of Next.js between
11.0.0and11.0.1usingpages/_error.jsandnext export - Not affected: Deployments on Vercel (vercel.com) are not affected
- Not affected: Deployments with
pages/404.js - Note that versions prior to 0.9.9 package
nextnpm package hosted a different utility (0.4.1 being the latest version of that codebase), and this advisory does not apply to those versions.
We recommend upgrading to the latest version of Next.js to improve the overall security of your application.
Patches
- Record
GHSA-vxf5-wxwp-m7g9- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
NVD
Next.js is an open source website development framework to be used with the React library. In affected versions specially encoded paths could be used when pages/_error.js was statically generated allowing an open redirect to occur to an external site. In general, this redirect does not directly harm users although can allow for phishing attacks by redirecting to an attacker's domain from a trusted domain. We recommend everyone to upgrade regardless of whether you can reproduce the issue or not. The issue has been patched in release 11.1.0.
- Record
CVE-2021-37699- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N - CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 5.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
OSV
Next.js is an open source website development framework to be used with the React library. In affected versions specially encoded paths could be used when pages/_error.js was statically generated allowing an open redirect to occur to an external site. In general, this redirect does not directly harm users although can allow for phishing attacks by redirecting to an attacker's domain from a trusted domain. We recommend everyone to upgrade regardless of whether you can reproduce the issue or not. The issue has been patched in release 11.1.0.
- Record
CVE-2021-37699- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-vxf5-wxwp-m7g9
Open Redirect in Next.js
Next.js is an open source website development framework to be used with the React library. In affected versions specially encoded paths could be used when pages/_error.js was statically generated, allowing an open redirect to occur to an external site. In general, this redirect does not directly harm users although it can allow for phishing attacks by redirecting to an attacker's domain from a trusted domain.
Impact
- Affected: Users of Next.js between
10.0.5and10.2.0 - Affected: Users of Next.js between
11.0.0and11.0.1usingpages/_error.jswithoutgetInitialProps - Affected: Users of Next.js between
11.0.0and11.0.1usingpages/_error.jsandnext export - Not affected: Deployments on Vercel (vercel.com) are not affected
- Not affected: Deployments with
pages/404.js - Note that versions prior to 0.9.9 package
nextnpm package hosted a different utility (0.4.1 being the latest version of that codebase), and this advisory does not apply to those versions.
We recommend upgrading to the latest version of Next.js to improve the overall security of your application.
Patches
- Record
GHSA-vxf5-wxwp-m7g9- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nextnpm |
0.9.9 up to 11.1.0 | 11.1.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-37699 is a medium vulnerability (CVSS 6.9) in Vercel Next.js, published August 11, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.03%, the 64th percentile. Fixed in next 11.1.0.