\n ```","image":"https://o3.security/opengraph.png","datePublished":"2018-12-20T00:29:00.303Z","dateModified":"2026-07-08T18:17:50.675419Z","url":"https://o3.security/vulnerability/CVE-2018-20302","inLanguage":"en","author":{"@id":"https://o3.security/#organization"},"publisher":{"@id":"https://o3.security/#organization"},"mainEntityOfPage":{"@type":"WebPage","@id":"https://o3.security/vulnerability/CVE-2018-20302"},"speakable":{"@type":"SpeakableSpecification","cssSelector":["h1",".vuln-summary",".vuln-severity",".vuln-mitigation"]},"about":[{"@type":"SoftwareApplication","name":"xain","applicationCategory":"Hex","softwareVersion":"0.6.2"}],"citation":[{"@type":"CreativeWork","name":"NVD","url":"https://nvd.nist.gov/vuln/detail/CVE-2018-20302"},{"@type":"CreativeWork","name":"OSV.dev","url":"https://osv.dev/vulnerability/CVE-2018-20302"},{"@type":"CreativeWork","name":"FIRST.org EPSS","url":"https://www.first.org/epss/api-data?cve=CVE-2018-20302"}]}\n ```","url":"https://o3.security/vulnerability/CVE-2018-20302","identifier":"CVE-2018-20302","datePublished":"2018-12-20T00:29:00.303Z","dateModified":"2026-07-08T18:17:50.675419Z","inLanguage":"en","license":"https://creativecommons.org/licenses/by/4.0/","keywords":["CVE-2018-20302","MEDIUM severity","CWE-79","CVE","vulnerability","security advisory"],"creator":{"@id":"https://o3.security/#organization"},"isAccessibleForFree":true,"citation":[{"@type":"CreativeWork","name":"NVD","url":"https://nvd.nist.gov/vuln/detail/CVE-2018-20302"},{"@type":"CreativeWork","name":"OSV.dev","url":"https://osv.dev/vulnerability/CVE-2018-20302"},{"@type":"CreativeWork","name":"FIRST.org EPSS","url":"https://www.first.org/epss/api-data?cve=CVE-2018-20302"}],"variableMeasured":[{"@type":"PropertyValue","name":"CVSS Base Score","value":6.1,"description":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"@type":"PropertyValue","name":"Severity","value":"MEDIUM"},{"@type":"PropertyValue","name":"EPSS Percentile","value":64}]}\n ```"}},{"@type":"Question","name":"How severe is CVE-2018-20302?","acceptedAnswer":{"@type":"Answer","text":"CVE-2018-20302 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance."}},{"@type":"Question","name":"Which packages are affected by CVE-2018-20302?","acceptedAnswer":{"@type":"Answer","text":"CVE-2018-20302 affects the following packages: xain (Hex). Ecosystems affected: Hex."}},{"@type":"Question","name":"How do I fix CVE-2018-20302?","acceptedAnswer":{"@type":"Answer","text":"Update xain to 0.6.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-20302 is resolved across your whole dependency graph."}},{"@type":"Question","name":"How do I detect CVE-2018-20302 in my Hex dependencies?","acceptedAnswer":{"@type":"Answer","text":"Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for xain, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version."}},{"@type":"Question","name":"How do I mitigate CVE-2018-20302 if there is no patch (or I can't update yet)?","acceptedAnswer":{"@type":"Answer","text":"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."}},{"@type":"Question","name":"How does O3 Security protect against CVE-2018-20302?","acceptedAnswer":{"@type":"Answer","text":"O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2018-20302 can be triaged on real exposure rather than presence alone."}},{"@type":"Question","name":"Is CVE-2018-20302 actively exploited in the wild?","acceptedAnswer":{"@type":"Answer","text":"Yes. There are 1 known exploit references for CVE-2018-20302, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization."}},{"@type":"Question","name":"What is the EPSS score for CVE-2018-20302?","acceptedAnswer":{"@type":"Answer","text":"CVE-2018-20302 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 64th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority."}},{"@type":"Question","name":"What type of vulnerability is CVE-2018-20302?","acceptedAnswer":{"@type":"Answer","text":"CVE-2018-20302 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure."}},{"@type":"Question","name":"When was CVE-2018-20302 published, and has it been updated?","acceptedAnswer":{"@type":"Answer","text":"CVE-2018-20302 was published on December 20, 2018 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting."}}]}
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💧
💧 Hex
Not in CISA KEV
MEDIUM severity

CVE-2018-20302 xain

MEDIUM

CVE-2018-20302 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in xain. 1 public exploit reference exists, so weaponization risk is real. A fix is available for xain — see the affected versions and patch details below.

Cross-site Scripting in xain

Also known asGHSA-5chx-gg25-v37m
Published
Dec 20, 2018
Updated
Jul 8, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Sep 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs64th percentile — riskier than 64% of all scored CVEsHighest risk

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-2018-20302 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 377,636 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

1 pkg affected
💧xain

Real-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

XSS is possible via the use of the order query parameter. An example request would look like:

http://host/ressources?order=%27><script>alert(1);</script>

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
💧Hexxainall versions0.6.2mix deps.update xain
Exploits & PoCs
1

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 dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for xain, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update xain to 0.6.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-20302 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2018-20302 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2018-20302. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

XSS is possible via the use of the order query parameter. An example request would look like: ``` http://host/ressources?order=%27><script>alert(1);</script> ```
O3 Security · Impact-Aware SCA

Is CVE-2018-20302 in your dependencies?

O3 Security finds CVE-2018-20302 across Hex dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2018-20302: xain XSS (Medium 6.1) | O3 Security