CVE-2026-40110 POC (Proof-of-Concept)

Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the allow_origin_pat configuration value. Because re.match() only anchors at the start of the string and does not require a full match, a pattern intended to match only a trusted domain (e.g., trusted.example.com) will also match any origin that begins with that domain followed by additional characters (e.g., trusted.example.com.evil.com). An attacker who controls such a domain can bypass the CORS origin restriction and make cross-origin requests to the Jupyter Server API from an untrusted site. This issue has been fixed in version 2.18.0.

Published: 2026-05-05

CVSS: 7.6

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

Download CVE-2026-40110 POC (Proof-of-Concept) here:

Tip: Download official Tor Browser at https://www.torproject.org/download/ to access .onion links.

https://hokyo.gr/poc-377-cve-2026-32689/

https://hokyo.gr/poc-516-cve-2026-43241/

https://hokyo.gr/poc-553-cve-2026-42503/

https://hokyo.gr/poc-7-cve-2026-7538/

https://hokyo.gr/poc-608-cve-2026-7976/