CVE-2023-26159 is a high-severity (CVSS 7.3) Improper Input Validation vulnerability in follow-redirects. 2 public exploit references exist, so weaponization risk is real. A fix is available for follow-redirects — see the affected versions and patch details below.
Follow Redirects improperly handles URLs in the url.parse() function
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-26159.
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-2023-26159 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 377,238 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.
follow-redirectsnpmDescription
Versions of the package follow-redirects before 1.15.4 are vulnerable to Improper Input Validation due to the improper handling of URLs by the url.parse() function. When new URL() throws an error, it can be manipulated to misinterpret the hostname. An attacker could exploit this weakness to redirect traffic to a malicious site, potentially leading to information disclosure, phishing attacks, or other security breaches.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | follow-redirects | all versions | 1.15.4npm install follow-redirects@1.15.4 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for follow-redirects, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update follow-redirects to 1.15.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26159 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-2023-26159 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-26159. 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.
follow-redirects is a transitive dependency of Grafana, and does not affect Red Hat Enterprise Linux 8.
| Product | Fixed in | Advisory |
|---|---|---|
| Migration Toolkit for Virtualization 2.5 | migration-toolkit-virtualization/mtv-console-plugin-rhel9:2.5.5-3 | RHBA-2024:0928 |
| MTA-6.2-RHEL-8 | mta/mta-rhel8-operator:6.2.2-3 | RHSA-2024:1027 |
| MTA-6.2-RHEL-9 | mta/mta-ui-rhel9:6.2.3-2 | RHSA-2024:3989 |
| MTA-7.0-RHEL-9 | mta/mta-cli-rhel9:7.0.3-16 | RHSA-2024:3316 |
| MTR 1.2.4 | follow-redirects | RHSA-2024:0720 |
| multicluster engine for Kubernetes 2.4 for RHEL 8 | multicluster-engine/console-mce-rhel8:v2.4.5-25 | RHBA-2024:3555 |
| NETWORK-OBSERVABILITY-1.5.0-RHEL-9 | network-observability/network-observability-console-plugin-rhel9:v1.5.0-89 | RHSA-2024:0853 |
| Red Hat Advanced Cluster Management for Kubernetes 2.9 for RHEL 8 | rhacm2/console-rhel8:v2.9.4-22 | RHBA-2024:3593 |
Frequently Asked Questions
Is CVE-2023-26159 in your dependencies?
O3 Security finds CVE-2023-26159 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.