kimi-cli · Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource
Affects kimi-cliSource GCVE Database
Not known to be exploited · CVSS 6.8 Medium : upgrade to 1.50.0 when convenient.
Data as of 30 Oct 2026, 06:59 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 6.8 |
|---|
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.50.0
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 27 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade kimi-cli to 1.50.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewkimi-clipkg:brew/kimi-cliOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to MCP SDK version 1.30.0 or later (for 1.x) or 2.2.0 or later (for 2.x) and enable the 'validate_token_resource' setting in 'AuthSettings' with the appropriate 'resource_server_url'. Also modify 'verify_token()' to return the token's audience as 'AccessToken.resource'. If upgrading is not feasible, implement manual audience ('aud') verification in the 'TokenVerifier' to reject tokens not intended for your server. Note that simply upgrading without enabling the setting does not enforce the fix. The setting will default to enabled in version 3.0.
Description
The Model Context Protocol (MCP) Python SDK versions 1.10.0 through 1.29.1 and 2.0.0 through 2.1.1 have a vulnerability in server-side bearer-token authentication. The SDK does not verify that a token's audience matches the intended server, allowing tokens issued for other services by the same authorization server to be accepted. This can lead to unauthorized access if tokens for different services are accepted. Fixed in versions 1.30.0+ and 2.2.0+, but enabling the audience check requires configuration changes. If upgrading is not possible, manual audience verification is recommended.
References
- github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23 (opens in a new tab)
- github.com/modelcontextprotocol/python-sdk/pull/3447 (opens in a new tab)
- github.com/modelcontextprotocol/python-sdk/pull/3451 (opens in a new tab)
- github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40 (opens in a new tab)
- github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512 (opens in a new tab)
- github.com/modelcontextprotocol/python-sdk (opens in a new tab)
- github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0 (opens in a new tab)
- github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0 (opens in a new tab)