CVE-2026-53840 — HIGH (7.1)

Q: How severe is CVE-2026-53840?

CVE-2026-53840 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2026-53840?

Check the references section above for vendor advisories and patch information. Affected products include: Openclaw Openclaw.

Vulnerability Description

OpenClaw before 2026.5.12 contains an information disclosure vulnerability in streamable-http MCP servers that forwards operator-configured custom headers during cross-origin redirects. Attackers controlling or compromising an MCP endpoint can redirect requests to exfiltrate sensitive headers like API keys or tenant-routing credentials to attacker-controlled origins.

CVSS Score

7.1

HIGH

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

LOW

Availability

NONE

Affected Products

Vendor	Product	Versions
Openclaw	Openclaw	< 2026.5.12

Related Weaknesses (CWE)

CWE-522

References

https://github.com/openclaw/openclaw/security/advisories/GHSA-rjxq-qqhf-8hwhVendor Advisory
https://www.vulncheck.com/advisories/openclaw-custom-header-leakage-via-mcp-streThird Party Advisory

FAQ

What is CVE-2026-53840?

CVE-2026-53840 is a vulnerability with a CVSS score of 7.1 (HIGH). OpenClaw before 2026.5.12 contains an information disclosure vulnerability in streamable-http MCP servers that forwards operator-configured custom headers during cross-origin redirects. Attackers cont...

How severe is CVE-2026-53840?

CVE-2026-53840 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-53840?

Check the references section above for vendor advisories and patch information. Affected products include: Openclaw Openclaw.