Vulnerability · Published May 12, 2026 · Assigned by VulnCheck

CVE-2026-45225Heym < 0.0.21 Path Traversal File Upload via upload_file()

High 7.6

In plain English

A high-severity path traversal in heym from heymrun. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities).

Severity (CVSS 3.1)7.6High

Exploit odds (30 days)0.4%top 70.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
heymrun	heym	0 – before 0.0.21

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L

References

https://github.com/heymrun/heym/releases/tag/v0.0.21 release-notes
https://github.com/heymrun/heym/pull/92 issue-tracking
https://github.com/heymrun/heym/commit/835843e6d2bf7d018cbb8e50f28f0426eaa20c84 patch
https://www.vulncheck.com/advisories/heym-path-traversal-file-upload-via-upload-file third-party-advisory