Is there a public exploit for CVE-2026-123271?

No public exploit for CVE-2026-123271 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-123271?

CVE-2026-123271 scores CVSS 5.1 (v4.0), rated medium.

What does CVE-2026-123271 affect?

CVE-2026-123271 affects diillson ChatCLI.

5.1 Medium

ChatCLI before v1.215.2 contains an improper validation vulnerability in the MCP OAuth login flow that uses server-supplied Protected…

CVE-2026-123271

ChatCLI before v1.215.2 contains an improper validation vulnerability in the MCP OAuth login flow that uses server-supplied Protected Resource Metadata as the resource indicator without checking it matches the configured server URL. A malicious MCP server can declare another resource on the same authorization server, obtain the user's bearer token for it, and replay that token against the other resource.

Assessment

CVSS: 5.1 (v4.0)
Severity: Medium
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 5 November 2026
Last updated: 5 November 2026
Affected: diillson · ChatCLI
Assigner: VulnCheck

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

At the source

EUVD (ENISA)

References

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