NextChat versions from 2.15.8 through 2.16.1 contain an improper URL validation vulnerability in the proxy endpoint that allows attackers to obtain the server's OpenAI API key. The x-base-url header is validated using substring matching instead of hostname parsing, allowing any URL containing 'api.openai.com' to pass validation and receive the server's credentials in the Authorization header.
History

Mon, 31 Aug 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sun, 30 Aug 2026 17:15:00 +0000

Type Values Removed Values Added
First Time appeared Chatgptnextweb
Chatgptnextweb nextchat
Vendors & Products Chatgptnextweb
Chatgptnextweb nextchat

Sun, 30 Aug 2026 13:30:00 +0000

Type Values Removed Values Added
Description NextChat versions from 2.15.8 through 2.16.1 contain an improper URL validation vulnerability in the proxy endpoint that allows attackers to obtain the server's OpenAI API key. The x-base-url header is validated using substring matching instead of hostname parsing, allowing any URL containing 'api.openai.com' to pass validation and receive the server's credentials in the Authorization header.
Title NextChat 2.15.8 through 2.16.1 OpenAI API Key Disclosure
First Time appeared Nextchat
Nextchat nextchat
Weaknesses CWE-20
CPEs cpe:2.3:a:nextchat:nextchat:*:*:*:*:*:*:*:*
Vendors & Products Nextchat
Nextchat nextchat
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-08-30T13:23:39.106Z

Updated: 2026-08-31T16:51:17.973Z

Reserved: 2026-08-30T13:06:02.366Z

Link: CVE-2026-82639

cve-icon Vulnrichment

Updated: 2026-08-31T16:50:36.617Z

cve-icon NVD

Status : Received

Published: 2026-08-30T14:17:03.750

Modified: 2026-08-31T17:17:45.737

Link: CVE-2026-82639

cve-icon Redhat

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