CVE-2024-43796 is a medium-severity (CVSS 5) Cross-site Scripting (XSS) vulnerability in express. A fix is available for express — see the affected versions and patch details below.
express vulnerable to XSS via response.redirect()
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-43796.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-43796 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
expressnpmDescription
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:
- The attacker MUST control the input to response.redirect()
- express MUST NOT redirect before the template appears
- the browser MUST NOT complete redirection before:
- the user MUST click on the link in the template
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | express | all versions | 4.20.0npm install express@4.20.0 |
| 📦npm | express | ≥ 5.0.0-alpha.1&&< 5.0.0 | 5.0.0npm install express@5.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for express, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update express to 4.20.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-43796 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-43796 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-43796. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Discovery 1 for RHEL 9 | discovery/discovery-server-rhel9:1.12.0-1 | RHSA-2025:1249 |
| HawtIO 4.0.0 for Red Hat build of Apache Camel 4 | express | RHSA-2024:11023 |
| NETWORK-OBSERVABILITY-1.7.0-RHEL-9 | network-observability/network-observability-cli-rhel9:v1.7.0-67 | RHSA-2024:8014 |
| Red Hat Developer Hub 1.3 on RHEL 9 | rhdh/rhdh-hub-rhel9:1.3-100 | RHBA-2024:7523 |
| Red Hat Migration Toolkit for Containers 1.8 | rhmtc/openshift-migration-ui-rhel8:v1.8.5-7 | RHSA-2024:10906 |
| Red Hat OpenShift Container Platform 4.17 | openshift4/nmstate-console-plugin-rhel9:v4.17.0-202501301204.p0.gcffdc60.assembly.stream.el9 | RHSA-2025:0875 |
| Red Hat OpenShift GitOps 1.12 | openshift-gitops-1/argocd-rhel8:v1.12.6-2 | RHSA-2024:8677 |
| Red Hat OpenShift GitOps 1.13 | openshift-gitops-1/argocd-rhel8:v1.13.2-4 | RHSA-2024:8581 |
Frequently Asked Questions
Is CVE-2024-43796 in your dependencies?
O3 Security finds CVE-2024-43796 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.