Path Traversal in Chainlit
CVE-2026-22218
Chainlit versions prior to 2.9.4 contain an arbitrary file read vulnerability in the /project/element update flow. An authenticated client can send a custom Element with a user-controlled path value, causing the server to copy the referenced file into the attacker’s session. The resulting element identifier (chainlitKey) can then be used to retrieve the file contents via /project/file/<chainlitKey>, allowing disclosure of any file readable by the Chainlit service.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.088 (94.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Chainlit — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (release-notes, Product, Release Notes, patch)
- disclosure@vulncheck.com (Exploit, technical-description, Third Party Advisory, exploit, Mitigation)
- disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-22218?
- CVE-2026-22218 is a medium-severity vulnerability in Chainlit, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-01-20.
- How severe is CVE-2026-22218?
- Medium severity. CVSS v3 base score is 6.5 out of 10.