CVE-2026-53840 json
OpenClaw < 2026.5.12 - Custom Header Leakage via MCP Streamable HTTP Cross-Origin Redirects
published 2026-06-16 4 mo ago modified 2026-06-17 4 mo ago also GHSA-rjxq-qqhf-8hwh , EUVD-2026-37142
- cvss
- 7.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 13%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm openclaw 2026.5.12
- OpenClaw OpenClaw 2026.5.12
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N |
| CNA | 4.0 | 6.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| GitHub | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | openclaw | <2026.5.12 |
2026.5.12 |
Affected products
- OpenClaw OpenClaw
Classification
References
-
github.com
/openclaw/openclaw/security/advisories/GHSA-rjxq-qqhf-8hwh
vendor-advisory, web
-
vulncheck.com
/advisories/openclaw-custom-header-leakage-via-mcp-streamable-http-cross-origin-redirects
third-party-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2026-53840
advisory
-
github.com
/openclaw/openclaw
package
Sources
- CVE List CVE-2026-53840
- GitHub Advisory GHSA-rjxq-qqhf-8hwh
- NVD CVE-2026-53840
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