CVE-2026-53837

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 91% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

OpenClaw before 2026.5.6 contains an improper access control vulnerability in Mattermost event handlers that fails to validate channel type metadata. Attackers can bypass intended DM policy decisions by sending crafted Mattermost events missing channel type information to process restricted content.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
9%
KEV
Not listed

Published

June 12, 2026

Last Modified

July 23, 2026

Advisory Details (2)

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

OpenClaw < 2026.5.6 - Missing Channel Type Validation in Mattermost Event Handlers | Advisories | VulnCheck

https://www.vulncheck.com/advisories/openclaw-missing-channel-type-validation-in-mattermost-event-handlers
github Patch Available

Mattermost handlers could fall open when channel type was missing · Advisory · openclaw/openclaw · GitHub

https://github.com/openclaw/openclaw/security/advisories/GHSA-gp79-m99v-gjmh

Vendor Advisories for CVE-2026-53837(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—2026.5.6—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 55× 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.

  1. 2026-07-27 07:53 UTCEG score recompute
  2. 2026-07-27 07:53 UTCGHSA enrichment
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-26 05:15 UTCEG score recompute
  5. 2026-07-26 05:15 UTCGHSA enrichment
  6. 2026-07-25 14:18 UTCEPSS rescore
  7. 2026-07-24 14:18 UTCEPSS rescore
  8. 2026-07-23 14:18 UTCEPSS rescore
  9. 2026-07-23 03:19 UTCEG score recompute▲ 1.60
  10. 2026-07-22 14:08 UTCEPSS rescore
  11. 2026-07-21 15:25 UTCEPSS rescore
  12. 2026-07-20 17:08 UTCEPSS rescore
  13. 2026-07-19 14:31 UTCEPSS rescore
  14. 2026-07-19 14:31 UTCEPSS rescore
  15. 2026-07-19 02:29 UTCEPSS rescore
  16. 2026-07-18 10:04 UTCEPSS rescore
  17. 2026-07-16 17:03 UTCEPSS rescore
  18. 2026-07-16 05:08 UTCGHSA enrichment
  19. 2026-07-15 16:57 UTCEPSS rescore
  20. 2026-07-15 16:57 UTCEPSS rescore
  21. 2026-07-15 02:00 UTCEPSS rescore
  22. 2026-07-15 02:00 UTCEPSS rescore
  23. 2026-07-13 22:31 UTCEPSS rescore
  24. 2026-07-13 11:18 UTCGHSA enrichment
  25. 2026-07-13 06:13 UTCEPSS rescore
Show 59 more
  1. 2026-07-13 06:13 UTCEPSS rescore
  2. 2026-07-12 05:46 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-11 08:27 UTCEPSS rescore
  5. 2026-07-10 17:27 UTCGHSA enrichment
  6. 2026-07-09 19:10 UTCEPSS rescore
  7. 2026-07-09 19:10 UTCEPSS rescore
  8. 2026-07-08 15:16 UTCEPSS rescore
  9. 2026-07-08 15:16 UTCEPSS rescore
  10. 2026-07-07 21:21 UTCGHSA enrichment
  11. 2026-07-07 13:46 UTCEPSS rescore
  12. 2026-07-07 13:46 UTCEPSS rescore
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-06 02:23 UTCEPSS rescore
  17. 2026-07-05 02:31 UTCEPSS rescore
  18. 2026-07-05 02:30 UTCEPSS rescore
  19. 2026-07-04 21:59 UTCGHSA enrichment
  20. 2026-07-04 06:31 UTCEPSS rescore
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-02 04:06 UTCGHSA enrichment
  23. 2026-07-01 15:07 UTCEPSS rescore
  24. 2026-06-30 23:22 UTCEPSS rescore
  25. 2026-06-29 14:06 UTCEPSS rescore
  26. 2026-06-29 14:06 UTCEPSS rescore
  27. 2026-06-29 10:16 UTCGHSA enrichment
  28. 2026-06-28 14:07 UTCEPSS rescore
  29. 2026-06-28 04:56 UTCEPSS rescore
  30. 2026-06-28 04:56 UTCEPSS rescore
  31. 2026-06-27 03:08 UTCEPSS rescore
  32. 2026-06-26 16:25 UTCGHSA enrichment
  33. 2026-06-25 13:49 UTCEPSS rescore
  34. 2026-06-24 14:05 UTCEPSS rescore
  35. 2026-06-23 22:35 UTCGHSA enrichment
  36. 2026-06-23 21:33 UTCEPSS rescore
  37. 2026-06-23 21:33 UTCEPSS rescore
  38. 2026-06-22 14:25 UTCEPSS rescore
  39. 2026-06-22 14:25 UTCEPSS rescore
  40. 2026-06-21 14:56 UTCEPSS rescore
  41. 2026-06-21 14:56 UTCEPSS rescore
  42. 2026-06-21 04:43 UTCGHSA enrichment
  43. 2026-06-21 01:59 UTCEPSS rescore
  44. 2026-06-21 01:59 UTCEPSS rescore
  45. 2026-06-19 19:26 UTCEPSS rescore
  46. 2026-06-19 19:26 UTCEPSS rescore
  47. 2026-06-18 17:52 UTCEPSS rescore
  48. 2026-06-18 17:52 UTCEPSS rescore
  49. 2026-06-18 10:07 UTCGHSA enrichment
  50. 2026-06-17 17:53 UTCEPSS rescore
  51. 2026-06-16 17:53 UTCEPSS rescore
  52. 2026-06-16 01:45 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  53. 2026-06-15 17:49 UTCEPSS rescore
  54. 2026-06-15 17:49 UTCEPSS rescore
  55. 2026-06-15 16:17 UTCGHSA enrichment
  56. 2026-06-14 23:18 UTCEPSS rescore
  57. 2026-06-13 23:00 UTCEPSS rescore
  58. 2026-06-12 22:17 UTCEG score recompute
  59. 2026-06-12 22:17 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-53837?
CVE-2026-53837 is a medium vulnerability published on June 12, 2026. OpenClaw before 2026.5.6 contains an improper access control vulnerability in Mattermost event handlers that fails to validate channel type metadata. Attackers can bypass intended DM policy decisions by sending crafted Mattermost events missing channel type information to process restricted content.
When was CVE-2026-53837 disclosed?
CVE-2026-53837 was first published in the National Vulnerability Database on June 12, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53837 actively exploited?
CVE-2026-53837 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 91.2% of all scored CVEs.
What is the CVSS score of CVE-2026-53837?
CVE-2026-53837 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-53837?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53837, 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-2026-53837

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