LowGHSA-qw6h-vgh9-j6wxCVE-2024-43796

express vulnerable to XSS via response.redirect()

Published 10 Sept 2024 · Updated 10 Sept 2026

Affected packages

expressnpm
Affected
<4.20.0
Fixed in
4.20.0
Update to the fixed version for your release line, for example:npm install express@4.20.0
expressnpm
Affected
>=5.0.0-alpha.1 <5.0.0
Fixed in
5.0.0
Update to the fixed version for your release line, for example:npm install express@5.0.0

Details

Impact

In express <4.20.0, passing untrusted user input - even after sanitizing it - to response.redirect() may execute untrusted code

Patches

this issue is patched in express 4.20.0

Workarounds

users are encouraged to upgrade to the patched version of express, but otherwise can workaround this issue by making sure any untrusted inputs are safe, ideally by validating them against an explicit allowlist

Details

successful exploitation of this vector requires the following:

1. The attacker MUST control the input to response.redirect() 1. express MUST NOT redirect before the template appears 1. the browser MUST NOT complete redirection before: 1. the user MUST click on the link in the template

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References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.