Path Traversal in Heymrun Heym
CVE-2026-45225
Heym before 0.0.21 contains a path traversal vulnerability in the file upload endpoint that allows authenticated users to write attacker-controlled files to arbitrary locations by supplying a crafted filename with traversal sequences. Attackers can exploit the unvalidated filename parameter in the upload_file() handler to bypass path restrictions and write, read, or delete files outside the intended storage directory.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L.
EPSS exploit prediction
EPSS: 0.004 (29.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.004 · change: -0.001
Affected products
- Heymrun Heym — versions 0, 835843e6d2bf7d018cbb8e50f28f0426eaa20c84
Weakness classification (CWE)
References
- heym 0.0.21 Release Notes (release-notes)
- github.com/heymrun/heym/pull/92 (issue-tracking, patch)
- github.com/heymrun/heym/commit/835843e6d2bf7d018cbb8e50f28f0426eaa20c84 (patch)
- www.vulncheck.com/advisories/heym-path-traversal-file-upload-via-upload-file (third-party-advisory)
Frequently asked questions
- What is CVE-2026-45225?
- CVE-2026-45225 is a high-severity vulnerability in Heymrun Heym, classified under Path Traversal. CVSS score: 7.6/10. Published 2026-05-12.
- How severe is CVE-2026-45225?
- High severity. CVSS v3 base score is 7.6 out of 10.