CVE-2026-56104

HIGH EPSS 16.9%
Published Jun 22, 20261w ago · Modified Jun 23, 20261w ago
8.8 CVSS 4.0
High
Find Similar
Published Jun 22, 2026 1w ago
Last Modified Jun 23, 2026 1w ago

Description

Chainlit before 2.10.1 contains a session hijacking vulnerability that allows unauthenticated attackers to restore and inherit authenticated user sessions by presenting a valid sessionId during WebSocket session restoration without ownership verification. Attackers can exploit the restore_existing_session path to assume a victim's permissions and roles, enabling unauthorized invocation of tools and access to data restricted to the authenticated victim.

CVSS Details

Base Score
8.8
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/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
Attack Vector Network
Attack Complexity High
Privileges Required Low
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
16.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-862 Missing Authorization Authorization

References 4

  • github.com https://github.com/Chainlit/chainlit/commit/5effb664f1e0af4a4f0a42fe63ea979676039a7f
  • github.com https://github.com/Chainlit/chainlit/pull/2857
  • github.com https://github.com/Chainlit/chainlit/releases/tag/2.10.1
  • vulncheck.com https://www.vulncheck.com/advisories/chainlit-session-hijacking-via-websocket-session-restoration

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.