Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/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
Primary rating from Vendor (VulnCheck) · only source for this CVE.
CVSS VectorVendor: VulnCheck
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/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
Lifecycle Timeline
3DescriptionCVE.org
Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.
AnalysisAI
A CORS misconfiguration in Jan up to version 0.8.4 allows network-adjacent attackers to bypass trusted host restrictions when the server is bound to 0.0.0.0, enabling unauthorized access to the OpenAI-compatible API for model enumeration, inference, and MCP tool invocation. A publicly available exploit exists, and CISA KEV does not list active exploitation; EPSS score is low at 0.19%, indicating limited real-world exploitation risk.
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An arbitrary file upload vulnerability in the /v1/app/appendFileSync interface of Jan v0.4.12 allows attackers to execut
An arbitrary file upload vulnerability in the /v1/app/writeFileSync interface of Jan v0.4.12 allows attackers to execute
Jan v0.4.12 was discovered to contain an arbitrary file read vulnerability via the /v1/app/readFileSync interface. Rated
Same weakness CWE-183 – Permissive List of Allowed Inputs
View allSame technique Authentication Bypass
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-48611
GHSA-4r96-7xrx-4gcr