SecuriTricks - CVE-2026-56104

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.

Product(s) Impacted

Vendor	Product	Versions
Chainlit	Chainlit	<2.10.1

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-862

Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	chainlit	chainlit	<2.10.1	/	/	/	/	/	/	/

References

https://github.com/Chainlit/chainlit/commit/5effb664f1e0af4a4f0a42fe63ea979676039a7f

https://github.com/Chainlit/chainlit/pull/2857

https://github.com/Chainlit/chainlit/releases/tag/2.10.1

https://www.vulncheck.com/advisories/chainlit-session-hijacking-via-websocket-session-restoration

CVSS Score

9.1 / 10

CVSS Data - 4.0

Attack Vector: NETWORK
Attack Complexity: HIGH
Attack Requirements: NONE
Privileges Required: NONE
User Interaction: NONE
Scope:
Confidentiality Impact: HIGH
Integrity Impact: HIGH
Availability Impact: NONE
Exploit Maturity: NOT_DEFINED

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/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

View Vector String

Timeline

Published: June 22, 2026, 4:16 p.m.
Last Modified: June 22, 2026, 6:16 p.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

CVE-2026-56104