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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.095 (95.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 95.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.092 · newest: 0.095 · change: +0.003
Affected products
- Chainlit — versions 0
Weakness classification (CWE)
References
- github.com/Chainlit/chainlit/releases/tag/2.9.4 (release-notes, Product, Release Notes, patch)
- www.zafran.io/resources/chainleak-critical-ai-framework-vulnerabilities-expose-… (Exploit, technical-description, Third Party Advisory, exploit, Mitigation)
- www.vulncheck.com/advisories/chainlit-arbitrary-file-read-via-project-element (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.