CVE-2021-3189
Open redirect in Slashify
The slashify package 1.0.0 for Node.js allows open-redirect attacks, as demonstrated by a localhost:3000///example.com/ substring.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
The slashify package 1.0.0 for Node.js allows open-redirect attacks, as demonstrated by a localhost:3000///example.com/ substring.
- Record
CVE-2021-3189- 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
CVE ListNo score
The slashify package 1.0.0 for Node.js allows open-redirect attacks, as demonstrated by a localhost:3000///example.com/ substring.
- Record
CVE-2021-3189- Updated
- 2026-11-02
EUVDEUVD-2021-0547No score
The slashify package 1.0.0 for Node.js allows open-redirect attacks, as demonstrated by a localhost:3000///example.com/ substring.
- Record
EUVD-2021-0547- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-f4hq-453j-p95f
Open redirect in Slashify
The package is an Express middleware that normalises routes by stripping any final slash, redirecting, for example, bookings/latest/ to bookings/latest. However, it does not validate the path it redirects to in any way. In particular, if the path starts with two slashes (or two backslashes, or a slash and a backslash, etc.) it may redirect to a different domain.
Consider the example from the docs. Assume we have run it and started a server on localhost:3000, then visiting localhost:3000///github.com/ redirects you to https://github.com.
Recommendation
This vulnerability is currently un-patched in the slashify package so there is no known safe version of this package. Discontinuing use of slashify is recommended.
- Record
GHSA-f4hq-453j-p95f- 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 - Weakness
- CWE-601
- Updated
- 2026-11-02
OSVGHSA-f4hq-453j-p95f
Open redirect in Slashify
The package is an Express middleware that normalises routes by stripping any final slash, redirecting, for example, bookings/latest/ to bookings/latest. However, it does not validate the path it redirects to in any way. In particular, if the path starts with two slashes (or two backslashes, or a slash and a backslash, etc.) it may redirect to a different domain.
Consider the example from the docs. Assume we have run it and started a server on localhost:3000, then visiting localhost:3000///github.com/ redirects you to https://github.com.
Recommendation
This vulnerability is currently un-patched in the slashify package so there is no known safe version of this package. Discontinuing use of slashify is recommended.
- Record
GHSA-f4hq-453j-p95f- 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 - Weakness
- CWE-601
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
slashifynpm | through 1.0.0 | None known |
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-2021-3189 is a medium vulnerability (CVSS 6.1) in Google Slashify, published February 5, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.53%, the 45th percentile. No source names a fixed version.