CVE-2026-53840

HIGHPre-NVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

Score 7.1 from GitHub Security Advisory published 2026-06-16. a secondary CVSS source baseline 7.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
7.1
EG Score
7.1(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity71% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
13%
KEV
Not listed

Published

June 16, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Jun 16, 2026
Patch available. Sources: github.
generic

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

https://www.vulncheck.com/advisories/openclaw-custom-header-leakage-via-mcp-streamable-http-cross-origin-redirects
github Patch Available

MCP Streamable HTTP redirects could forward configured custom headers to another origin · Advisory · openclaw/openclaw · GitHub

https://github.com/openclaw/openclaw/security/advisories/GHSA-rjxq-qqhf-8hwh

Vendor Advisories for CVE-2026-53840(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
openclaw—2026.5.12—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 51× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 115 total refreshes for this CVE.

  1. 2026-08-26 14:46 UTCEPSS rescore
  2. 2026-08-25 13:49 UTCEPSS rescore
  3. 2026-08-24 23:24 UTCEG score recompute
  4. 2026-08-23 09:25 UTCEG score recompute
  5. 2026-08-23 00:19 UTCEPSS rescore
  6. 2026-08-21 23:49 UTCEPSS rescore
  7. 2026-08-21 09:46 UTCEG score recompute
  8. 2026-08-20 22:55 UTCEPSS rescore
  9. 2026-08-20 08:33 UTCEG score recompute
  10. 2026-08-19 17:04 UTCEPSS rescore
  11. 2026-08-19 13:06 UTCEG score recompute
  12. 2026-08-18 13:48 UTCEPSS rescore
  13. 2026-08-17 13:47 UTCEPSS rescore
  14. 2026-08-16 16:23 UTCEG score recompute
  15. 2026-08-16 14:56 UTCEPSS rescore
  16. 2026-08-16 03:58 UTCEG score recompute
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  21. 2026-08-13 22:00 UTCEPSS rescore
  22. 2026-08-13 01:17 UTCEG score recompute
  23. 2026-08-12 13:51 UTCEPSS rescore
  24. 2026-08-12 00:26 UTCEG score recompute
  25. 2026-08-11 12:00 UTCEG score recompute
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  1. 2026-08-11 00:00 UTCEPSS rescore
  2. 2026-08-09 22:43 UTCEG score recompute
  3. 2026-08-09 13:46 UTCEPSS rescore
  4. 2026-08-08 21:51 UTCEG score recompute
  5. 2026-08-08 16:37 UTCEPSS rescore
  6. 2026-08-07 21:00 UTCEG score recompute
  7. 2026-08-06 20:09 UTCEG score recompute
  8. 2026-08-06 13:47 UTCEPSS rescore
  9. 2026-08-05 19:18 UTCEG score recompute
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  11. 2026-08-04 15:36 UTCEG score recompute
  12. 2026-08-04 15:10 UTCEPSS rescore
  13. 2026-08-04 10:39 UTCEPSS rescore
  14. 2026-08-03 22:29 UTCEG score recompute
  15. 2026-08-03 10:36 UTCEPSS rescore
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  17. 2026-08-02 02:27 UTCEPSS rescore
  18. 2026-08-01 08:19 UTCEG score recompute
  19. 2026-08-01 04:16 UTCEPSS rescore
  20. 2026-07-30 23:33 UTCEG score recompute
  21. 2026-07-30 16:28 UTCEPSS rescore
  22. 2026-07-30 04:13 UTCEG score recompute
  23. 2026-07-30 01:30 UTCEPSS rescore
  24. 2026-07-29 03:02 UTCEG score recompute
  25. 2026-07-28 15:37 UTCEPSS rescore
  26. 2026-07-28 01:37 UTCEG score recompute
  27. 2026-07-26 19:48 UTCEG score recompute
  28. 2026-07-26 14:54 UTCEPSS rescore
  29. 2026-07-25 14:18 UTCEPSS rescore
  30. 2026-07-24 14:18 UTCEPSS rescore
  31. 2026-07-23 14:18 UTCEPSS rescore
  32. 2026-07-23 03:19 UTCEG score recompute
  33. 2026-07-22 14:08 UTCEPSS rescore
  34. 2026-07-21 15:25 UTCEPSS rescore
  35. 2026-07-20 17:08 UTCEPSS rescore
  36. 2026-07-19 14:31 UTCEPSS rescore
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  38. 2026-07-19 02:29 UTCEPSS rescore
  39. 2026-07-18 10:04 UTCEPSS rescore
  40. 2026-07-16 17:03 UTCEPSS rescore
  41. 2026-07-15 16:57 UTCEPSS rescore
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  43. 2026-07-15 02:00 UTCEPSS rescore
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  45. 2026-07-13 22:31 UTCEPSS rescore
  46. 2026-07-13 06:13 UTCEPSS rescore
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  48. 2026-07-12 05:46 UTCEPSS rescore
  49. 2026-07-11 08:27 UTCEPSS rescore
  50. 2026-07-11 08:27 UTCEPSS rescore
  51. 2026-07-09 19:10 UTCEPSS rescore
  52. 2026-07-09 19:10 UTCEPSS rescore
  53. 2026-07-08 15:16 UTCEPSS rescore
  54. 2026-07-08 15:16 UTCEPSS rescore
  55. 2026-07-07 13:46 UTCEPSS rescore
  56. 2026-07-07 13:46 UTCEPSS rescore
  57. 2026-07-06 16:27 UTCEPSS rescore
  58. 2026-07-06 16:27 UTCEPSS rescore
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  61. 2026-07-05 02:31 UTCEPSS rescore
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  63. 2026-07-04 06:31 UTCEPSS rescore
  64. 2026-07-04 06:31 UTCEPSS rescore
  65. 2026-07-01 15:07 UTCEPSS rescore
  66. 2026-06-30 23:22 UTCEPSS rescore
  67. 2026-06-29 14:06 UTCEPSS rescore
  68. 2026-06-29 14:06 UTCEPSS rescore
  69. 2026-06-28 14:07 UTCEPSS rescore
  70. 2026-06-28 04:56 UTCEPSS rescore
  71. 2026-06-28 04:56 UTCEPSS rescore
  72. 2026-06-27 03:08 UTCEPSS rescore
  73. 2026-06-25 13:49 UTCEPSS rescore
  74. 2026-06-24 14:05 UTCEPSS rescore
  75. 2026-06-23 21:33 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2026-53840?
CVE-2026-53840 is a high vulnerability published on June 16, 2026. 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…
When was CVE-2026-53840 disclosed?
CVE-2026-53840 was first published in the National Vulnerability Database on June 16, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53840 actively exploited?
CVE-2026-53840 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 87.2% of all scored CVEs.
What is the CVSS score of CVE-2026-53840?
CVE-2026-53840 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-53840?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53840, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-53840

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