ericc-ch copilot-api Token Endpoint server.ts cors cross-domain policy

published 2026-04-20 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-23923

cvss: 7.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits: 0; none known

A vulnerability was found in ericc-ch copilot-api up to 0.7.0. The impacted element is the function cors of the file src/server.ts of the component Token Endpoint. Performing a manipulation results in permissive cross-domain policy with untrusted domains. It is possible to initiate the attack remotely. The exploit has been made public and could be used.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 6 mo ago (2026-04-20)

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/August829/CVEP/issues/31 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA	3.0	7.3	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P/E:POC/RL:ND/RC:UR
CNA	4.0	5.5	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CNA	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

ericc-ch copilot-api

Classification

Weakness

CWE-942 Permissive Cross-domain Security Policy with Untrusted Domains
CWE-346 Origin Validation Error

References

github.com /August829/CVEP/issues/31
exploit, issue-tracking
vuldb.com /vuln/358300
vdb-entry, technical-description
vuldb.com /vuln/358300/cti
signature, permissions-required
vuldb.com /submit/794601
third-party-advisory

Sources

CVE List CVE-2026-6662
NVD CVE-2026-6662

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary