Directory traversal vulnerability in H2O before 1.4.5 and 1.5.x before 1.5.0-beta2, when the file.dir directive is enabled, allows remote attackers to read arbitrary files via a crafted URL.
Conclusion & alert: CVE-2015-5638 is rated Moderate Risk (44.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.65%). Core evidence: EPSS rose +1.41% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.24% | 1.65% | +1.41% |
| 2 | 2025-03-30 | 0.29% | 0.24% | -0.05% |
| 3 | 2025-03-29 | — | 0.29% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2015-5638 unimportant priority: Debian including 1 source packages (h2o), 2 status rows across 2 suites (bookworm, bullseye): resolved 2. | https://security-tracker.debian.org/tracker/CVE-2015-5638 |
| URL | Tags |
|---|---|
| http://jvn.jp/en/jp/JVN65602714/index.html | Vendor Advisory |
| http://jvndb.jvn.jp/jvndb/JVNDB-2015-000136 | Vendor Advisory |
| https://h2o.examp1e.net/vulnerabilities.html#CVE-2015-5638 | Vendor Advisory |