CVE-2026-15576

MEDIUMPre-NVD 6.96.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 81% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
6.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.9Exploit: None knownExposed: 0

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

Improper authentication in the agent receiver of Checkmk <2.5.0p10 allows an unauthenticated remote attacker to bypass mutual TLS client certificate verification of relay endpoints by supplying a fixed placeholder identity in the request URL, resulting in limited impact on integrity and availability. Only the Cloud, Ultimate and Ultimate MT editions are affected, as other editions do not expose relay endpoints.

CVSS v3
6.9
EG Score
6.9(medium)
EG Risk
46(Track)
EG Risk 46/100SSVC: 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
Severity69% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

August 21, 2026

Last Modified

August 26, 2026

Advisory Details (1)

Auto-updated Aug 21, 2026
No patch confirmed yet.
generic

Werk #20174: Agent receiver: reject mTLS requests without a client certificate

https://checkmk.com/werk/20174

Vendor Advisories for CVE-2026-15576(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 79× 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. 2026-09-21 00:15 UTCEG score recompute
  2. 2026-09-21 00:15 UTCGHSA enrichment
  3. 2026-09-20 00:23 UTCEG score recompute
  4. 2026-09-20 00:23 UTCGHSA enrichment
  5. 2026-09-19 00:31 UTCEG score recompute
  6. 2026-09-19 00:31 UTCGHSA enrichment
  7. 2026-09-18 19:27 UTCEPSS rescore
  8. 2026-09-18 00:37 UTCEG score recompute
  9. 2026-09-18 00:37 UTCGHSA enrichment
  10. 2026-09-17 00:46 UTCEG score recompute
  11. 2026-09-17 00:46 UTCGHSA enrichment
  12. 2026-09-16 14:07 UTCEPSS rescore
  13. 2026-09-16 05:14 UTCEPSS rescore
  14. 2026-09-16 00:54 UTCEG score recompute
  15. 2026-09-16 00:54 UTCGHSA enrichment
  16. 2026-09-15 01:02 UTCGHSA enrichment
  17. 2026-09-14 01:10 UTCEG score recompute
  18. 2026-09-14 01:10 UTCGHSA enrichment
  19. 2026-09-13 16:46 UTCEPSS rescore
  20. 2026-09-13 01:19 UTCEG score recompute
  21. 2026-09-13 01:19 UTCGHSA enrichment
  22. 2026-09-12 15:00 UTCEPSS rescore
  23. 2026-09-12 01:27 UTCEG score recompute
  24. 2026-09-12 01:27 UTCGHSA enrichment
  25. 2026-09-11 14:52 UTCEPSS rescore
Show 59 more
  1. 2026-09-11 09:36 UTCEPSS rescore
  2. 2026-09-11 01:35 UTCEG score recompute
  3. 2026-09-11 01:35 UTCGHSA enrichment
  4. 2026-09-10 09:34 UTCEPSS rescore
  5. 2026-09-10 01:44 UTCGHSA enrichment
  6. 2026-09-09 01:48 UTCEG score recompute
  7. 2026-09-09 01:48 UTCGHSA enrichment
  8. 2026-09-08 22:00 UTCEPSS rescore
  9. 2026-09-07 20:43 UTCEG score recompute
  10. 2026-09-07 20:43 UTCGHSA enrichment
  11. 2026-09-07 16:01 UTCEPSS rescore
  12. 2026-09-06 20:51 UTCEG score recompute
  13. 2026-09-06 20:51 UTCGHSA enrichment
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-05 20:59 UTCEG score recompute
  16. 2026-09-05 20:59 UTCGHSA enrichment
  17. 2026-09-04 21:07 UTCEG score recompute
  18. 2026-09-04 21:07 UTCGHSA enrichment
  19. 2026-09-04 05:06 UTCEPSS rescore
  20. 2026-09-03 21:02 UTCGHSA enrichment
  21. 2026-09-02 21:07 UTCEG score recompute
  22. 2026-09-02 21:07 UTCGHSA enrichment
  23. 2026-09-02 14:11 UTCEPSS rescore
  24. 2026-09-01 18:54 UTCEG score recompute
  25. 2026-09-01 18:54 UTCGHSA enrichment
  26. 2026-09-01 13:53 UTCEPSS rescore
  27. 2026-09-01 04:39 UTCEPSS rescore
  28. 2026-08-31 19:01 UTCEG score recompute
  29. 2026-08-31 19:01 UTCGHSA enrichment
  30. 2026-08-30 19:17 UTCEPSS rescore
  31. 2026-08-30 18:40 UTCEG score recompute
  32. 2026-08-30 18:40 UTCGHSA enrichment
  33. 2026-08-30 01:22 UTCEPSS rescore
  34. 2026-08-29 18:48 UTCEG score recompute
  35. 2026-08-29 18:48 UTCGHSA enrichment
  36. 2026-08-28 21:41 UTCEPSS rescore
  37. 2026-08-28 18:55 UTCGHSA enrichment
  38. 2026-08-27 19:01 UTCEG score recompute
  39. 2026-08-27 19:01 UTCGHSA enrichment
  40. 2026-08-27 14:25 UTCEPSS rescore
  41. 2026-08-26 19:02 UTCEG score recompute
  42. 2026-08-26 19:02 UTCGHSA enrichment
  43. 2026-08-26 14:46 UTCEPSS rescore
  44. 2026-08-26 11:39 UTCEG score recompute
  45. 2026-08-26 11:39 UTCGHSA enrichment
  46. 2026-08-25 13:48 UTCEPSS rescore
  47. 2026-08-25 11:48 UTCEG score recompute
  48. 2026-08-25 11:48 UTCGHSA enrichment
  49. 2026-08-24 11:54 UTCEG score recompute
  50. 2026-08-24 11:54 UTCGHSA enrichment
  51. 2026-08-23 12:02 UTCEG score recompute
  52. 2026-08-23 12:02 UTCGHSA enrichment
  53. 2026-08-23 00:19 UTCEPSS rescore
  54. 2026-08-22 12:11 UTCGHSA enrichment
  55. 2026-08-21 12:19 UTCEG score recompute
  56. 2026-08-21 12:04 UTCEG score recompute
  57. 2026-08-21 11:21 UTCEG score recompute
  58. 2026-08-21 11:17 UTCEG score recompute
  59. 2026-08-21 11:14 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-15576?
CVE-2026-15576 is a medium vulnerability published on August 21, 2026. Improper authentication in the agent receiver of Checkmk <2.5.0p10 allows an unauthenticated remote attacker to bypass mutual TLS client certificate verification of relay endpoints by supplying a fixed placeholder identity in the request URL, resulting in limited impact on integrity and…
When was CVE-2026-15576 disclosed?
CVE-2026-15576 was first published in the National Vulnerability Database on August 21, 2026, with the most recent update on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-15576 actively exploited?
CVE-2026-15576 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 80.7% of all scored CVEs.
What is the CVSS score of CVE-2026-15576?
CVE-2026-15576 has a CVSS v3 base score of 6.9 (NVD).
How do I remediate CVE-2026-15576?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-15576, 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

Explore the affected products and dependency analysis for CVE-2026-15576

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