CVE-2026-53840

HIGH

OpenClaw < 2026.5.12 - Custom Header Leakage via MCP Streamable HTTP Cross-Origin Redirects

Title source: cna
STIX 2.1

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.

References (2)

Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-rjxq-qqhf-8hwh)
https://github.com/openclaw/openclaw/security/advisories/GHSA-rjxq-qqhf-8hwh
Third Party Advisory third-party-advisory
VulnCheck Advisory: OpenClaw < 2026.5.12 - Custom Header Leakage via MCP Streamable HTTP Cross-Origin Redirects
https://www.vulncheck.com/advisories/openclaw-custom-header-leakage-via-mcp-streamable-http-cross-origin-redirects

Scores

CVSS v3 7.1
EPSS 0.0022
EPSS Percentile 12.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-522
Status published
Products (5)
npm/openclaw 0 - 2026.5.12npm
openclaw/openclaw 2026.5.12 beta1 (8 CPE variants)
OpenClaw/OpenClaw < 2026.5.12
openclaw/openclaw < 2026.5.12
OpenClaw/OpenClaw 2026.5.12
Published Jun 16, 2026
Tracked Since Jun 17, 2026