Full Report
Update Chainlit to the latest version ASAP Two "easy-to-exploit" vulnerabilities in the popular open-source AI framework Chainlit put major enterprises' cloud environments at risk of leaking data or even full takeover, according to cyber-threat exposure startup Zafran.…
Analysis Summary
# Vulnerability: Chainlit Arbitrary File Read and SSRF Leading to Data Leakage and Account Takeover
## CVE Details
- CVE ID: CVE-2026-22218 (Arbitrary File Read)
- CVE ID: CVE-2026-22219 (Server-Side Request Forgery)
- CVSS Score: Not explicitly provided, but described as "easy-to-exploit" leading to data leaks and takeover.
- CWE: Not explicitly provided.
## Affected Systems
- Products: Chainlit (Python open-source AI framework)
- Versions: Versions prior to 2.9.4
- Configurations: Affects backend servers hosting AI applications integrated with this framework.
## Vulnerability Description
Two vulnerabilities exist in how Chainlit handles "elements" (content attached to messages, such as files or images), specifically when processing a malicious update element request with a tampered custom element.
1. **CVE-2026-22218 (Arbitrary File Read):** Allows an attacker to read arbitrary files on the server, notably `/proc/self/environ`, leading to the exfiltration of sensitive environment variables such as API keys, credentials (e.g., AWS\_SECRET\_KEY), internal IPs, and authentication secrets (CHAINLIT\_AUTH\_SECRET). Exposure of the authentication secret can enable account takeover if combined with inferred user identifiers.
2. **CVE-2026-22219 (SSRF):** Found in the SQLAlchemy data layer, this vulnerability is also triggered via the tampered custom element. It allows an attacker to probe internal services or retrieve files downloaded to an internal location via manipulated element properties (e.g., "chainlit key"). This can be chained with the file read vulnerability to facilitate access to internal REST APIs and conversation history.
## Exploitation
- Status: Not explicitly indicated as exploited in the wild, but PoC information is implied through the detailed technical description by Zafran.
- Complexity: Low ("easy-to-exploit"). An attacker only needs to send a simple command and change one value.
- Attack Vector: Network (via malicious element requests sent to the internet-facing application).
## Impact
- Confidentiality: High (Leaked environment variables include API keys, cloud credentials, internal IPs, and potential access to conversation history).
- Integrity: High (Potential for privilege escalation or misuse of leaked credentials/API keys).
- Availability: Potentially increased if internal systems are probed via SSRF. Full takeover of user accounts via forged tokens is possible.
## Remediation
### Patches
- Update Chainlit to version **2.9.4** or later. The fix was released in December 2025 (one month after disclosure in November 2025).
### Workarounds
- No explicit workarounds were listed in the source material. Immediate patching is strongly advised.
## Detection
- Indicators of Compromise: Look for unusual attempts to read system files like `/proc/self/environ` originating from the Chainlit application process logs. Monitoring for unauthorized access to internal network services or resources documented in environment variables ($\text{CHAINLIT\_AUTH\_SECRET}$, cloud provider keys).
- Detection methods and tools: Network monitoring for unusual egress traffic patterns from the AI application server. Log analysis focusing on element handling/processing modules within the Chainlit backend.
## References
- Vendor advisories: Chainlit release tag 2.9.4 (GitHub)
- Relevant links - defanged:
- h**ps://github.com/Chainlit/chainlit/releases/tag/2.9.4
- h**ps://chainlit.io/