Which versions of Chainlit are affected by CVE-2026-22218?

Chainlit versions prior to 2.9.4 contain an arbitrary file read vulnerability affecting authenticated users, with publicly available exploit code now in circulation.. A patch is available.

Is there a public PoC exploit available for CVE-2026-22218?

Yes, a public proof-of-concept exploit is available for CVE-2026-22218. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-22218?

Within 24 hours, conduct a complete inventory of Chainlit deployments and record version numbers. Within 7 days, upgrade all instances to Chainlit version 2.9.4 or later. Within 30 days, analyze file access logs from the exposure period to identify potential data exfiltration, restrict the Chainlit service process to minimum required file system permissions, and review any exposed credential material for compromise indicators.

Chainlit CVE-2026-22218

Q: What is the CVSS score of CVE-2026-22218?

CVE-2026-22218 has a CVSS 4.0 base score of 7.1 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

HIGH

Path Traversal (CWE-22)

2026-01-20 disclosure@vulncheck.com

Path Traversal Chainlit

7.1

CVSS 4.0 · Vendor: vulncheck

Severity by source

Vendor (vulncheck) PRIMARY

7.1 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

6.5 MEDIUM

Authenticated (PR:L) low-complexity network request to a standard endpoint yields arbitrary file read, so C:H with no integrity or availability impact and unchanged scope.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (vulncheck).

CVSS VectorVendor: vulncheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

Jul 14, 2026 - 17:09 vuln.today

v3 (cvss_changed)

Source Code Evidence Fetched

Jul 14, 2026 - 17:07 vuln.today

Analysis Updated

Jul 14, 2026 - 17:07 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Jul 14, 2026 - 16:22 vuln.today

cvss_changed

Severity Changed

Jul 14, 2026 - 16:22 NVD

MEDIUM HIGH

CVSS changed

Jul 14, 2026 - 16:22 NVD

6.5 (MEDIUM) 7.1 (HIGH)

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Feb 02, 2026 - 20:56 vuln.today

Public exploit code

CVE Published

Jan 20, 2026 - 00:15 nvd

MEDIUM 6.5

DescriptionCVE.org

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.

AnalysisAI

Arbitrary file read in Chainlit versions prior to 2.9.4 lets an authenticated user disclose any file readable by the Chainlit service process by abusing the /project/element update flow with a user-controlled path. The server copies the referenced file into the attacker's session and returns a chainlitKey usable at /project/file/<chainlitKey> to exfiltrate contents. Publicly available exploit code exists (documented as part of the 'ChainLeak' research by Zafran), though EPSS is very low (0.03%) and it is not on CISA KEV.