GHSA-cmfh-8f8r-fj96 — phoenix
MEDIUMGHSA-cmfh-8f8r-fj96 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in phoenix. A fix is available for phoenix — see the affected versions and patch details below.
Phoenix Arbitrary URL Redirect
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
GHSA-cmfh-8f8r-fj96 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 377,166 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
phoenix💧phoenix💧phoenixReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.
Description
The Phoenix team designed Phoenix.Controller.redirect/2 to protect against redirects allowing user input to redirect to an external URL where your application code otherwise assumes a local path redirect. This is why the :to option is used for “local” URL redirects and why you must pass the :external option to intentionally allow external URLs to be redirected to. It has been disclosed that carefully crafted user input may be treated by some browsers as an external URL. An attacker can use this vulnerability to aid in social engineering attacks. The most common use would be to create highly believable phishing attacks. For example, the following user input would pass local URL validation, but be treated by Chrome and Firefox as external URLs:
http://localhost:4000/?redirect=/\nexample.com
Not all browsers are affected, but latest Chrome and Firefox will issue a get request for example.com and successfully redirect externally
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💧Hex | phoenix | all versions | 1.0.6mix deps.update phoenix |
| 💧Hex | phoenix | ≥ 1.1.0&&< 1.1.8 | 1.1.8mix deps.update phoenix |
| 💧Hex | phoenix | ≥ 1.2.0&&< 1.2.3 | 1.2.3mix deps.update phoenix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phoenix, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update phoenix to 1.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cmfh-8f8r-fj96 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 GHSA-cmfh-8f8r-fj96 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-cmfh-8f8r-fj96. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect GHSA-cmfh-8f8r-fj96
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id ghsa-cmfh-8f8r-fj96 -u https://target- Template
- Phoenix Framework - Open Redirect
- Severity
- medium
- Impact
- An attacker can craft a malicious URL that redirects users to a malicious website, leading to potential phishing attacks.
- Remediation
- Apply the latest security patches or upgrade to a patched version of the Phoenix Framework.
Template by ProjectDiscovery nuclei-templates (0x_Akoko), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is GHSA-cmfh-8f8r-fj96 in your dependencies?
O3 Security finds GHSA-cmfh-8f8r-fj96 across Hex dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.