Answer in brief
CVE-2024-43796 records a Medium severity (CVSS 5.0) vulnerability in express vulnerable to XSS via response.redirect(). The current sources do not mark it as known exploited. The current feed maps express (npm), express (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps express (npm), express (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| expressnpm | >=0 <4.20.0 | 4.20.0 |
| expressnpm | >=5.0.0-alpha.1 <5.0.0 | 5.0.0 |
Published upstream
Sep 10, 2024
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Sep 10, 2026
### 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
Quoted source text, attributed separately from HOL analysis.