CVE-2026-101062

HIGH
Published Sep 27, 2026 Modified Sep 30, 2026 CWE-863

Description

Obot before v0.23.0 (affected versions <= v0.22.1) running with OBOT_SERVER_ENABLE_AUTHENTICATION=true exposes OAuth dynamic client registration without authentication and without any restriction on the redirect URIs a client may register. Because the authorization flow auto-completes for an already logged-in user with no consent screen, an attacker who registers a client pointing at their own domain and induces a logged-in victim to visit a single crafted authorization URL receives an authorization code at the attacker-controlled redirect URI and can exchange it for an access token and refresh token. The token minted by the MCP OAuth flow carries the victim's full group set in the JWT, and Obot validated only the issuer and not the audience, so the token is accepted as a bearer token against any Obot API endpoint the victim can access rather than being scoped to the requested MCP server, allowing the attacker to read or modify the victim's resources until the token is revoked. v0.23.0 adds a consent screen, restricts MCP OAuth tokens to the MCP involved in the request, and enforces audience validation.

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CVSS v3.1 Score

8.8
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0034
Probability of exploitation
0.25%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-863 Incorrect Authorization

References

Frequently Asked Questions

What is CVE-2026-101062? +
Obot before v0.23.0 (affected versions <= v0.22.1) running with OBOT_SERVER_ENABLE_AUTHENTICATION=true exposes OAuth dynamic client registration without authentication and without any restriction on the redirect URIs a client may register. Because the authorization flow auto-completes for an already logged-in user with no consent screen, an attacker who registers a client pointing at their own domain and induces a logged-in victim to visit a single crafted authorization URL receives an authorization code at the attacker-controlled redirect URI and can exchange it for an access token and refresh token. The token minted by the MCP OAuth flow carries the victim's full group set in the JWT, and Obot validated only the issuer and not the audience, so the token is accepted as a bearer token against any Obot API endpoint the victim can access rather than being scoped to the requested MCP server, allowing the attacker to read or modify the victim's resources until the token is revoked. v0.23.0 adds a consent screen, restricts MCP OAuth tokens to the MCP involved in the request, and enforces audience validation. It has a CVSS v3.1 base score of 8.8 (HIGH).
How severe is CVE-2026-101062? +
CVE-2026-101062 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0034, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-101062? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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