CVE-2026-9549

MEDIUMNVD 4.84.8—
EchelonGraph scoreHIGH confidence

Score 4.8 from GitHub Security Advisory published 2026-06-08. NVD baseline CVSS 4.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
4.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.8Exploit: NoneExposed: 0

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

Stored cross-site scripting in the service discovery active check output in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can configure active or custom checks to inject malicious HTML or JavaScript into check output that executes in the browser of an admin or a user with host read permissions when they run the check on the service discovery page.

CVSS v3
4.8
EG Score
4.8(high)
EPSS
3.9%
KEV
Not listed

Published

June 8, 2026

Last Modified

June 8, 2026

Advisory Details (1)

Auto-updated Jun 16, 2026
No patch confirmed yet.
generic

Werk #17993: Fix XSS in service discovery active check output

https://checkmk.com/werk/17993

Vendor Advisories for CVE-2026-9549(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 18× in last 7d / 83× 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. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 02:23 UTCEPSS rescore
  3. 2026-07-05 17:54 UTCEG score recompute
  4. 2026-07-05 17:54 UTCGHSA enrichment
  5. 2026-07-05 02:31 UTCEPSS rescore
  6. 2026-07-04 15:11 UTCEG score recompute
  7. 2026-07-04 15:10 UTCGHSA enrichment
  8. 2026-07-04 06:31 UTCEPSS rescore
  9. 2026-07-03 09:30 UTCEG score recompute
  10. 2026-07-03 09:29 UTCGHSA enrichment
  11. 2026-07-02 06:44 UTCEG score recompute
  12. 2026-07-02 06:44 UTCGHSA enrichment
  13. 2026-07-01 15:07 UTCEPSS rescore
  14. 2026-07-01 07:49 UTCEG score recompute
  15. 2026-07-01 07:48 UTCGHSA enrichment
  16. 2026-06-30 23:22 UTCEPSS rescore
  17. 2026-06-30 08:51 UTCEG score recompute
  18. 2026-06-30 08:51 UTCGHSA enrichment
  19. 2026-06-29 14:06 UTCEPSS rescore
  20. 2026-06-29 09:49 UTCEG score recompute
  21. 2026-06-29 09:49 UTCGHSA enrichment
  22. 2026-06-28 14:07 UTCEPSS rescore
  23. 2026-06-28 10:43 UTCEG score recompute
  24. 2026-06-28 10:43 UTCGHSA enrichment
  25. 2026-06-28 04:56 UTCEPSS rescore
Show 58 more
  1. 2026-06-27 11:48 UTCEG score recompute
  2. 2026-06-27 11:48 UTCGHSA enrichment
  3. 2026-06-27 03:08 UTCEPSS rescore
  4. 2026-06-26 12:51 UTCEG score recompute
  5. 2026-06-26 12:51 UTCGHSA enrichment
  6. 2026-06-25 13:50 UTCEPSS rescore
  7. 2026-06-25 07:13 UTCEG score recompute
  8. 2026-06-25 07:13 UTCGHSA enrichment
  9. 2026-06-24 14:05 UTCEPSS rescore
  10. 2026-06-24 08:17 UTCEG score recompute
  11. 2026-06-24 08:17 UTCGHSA enrichment
  12. 2026-06-23 21:33 UTCEPSS rescore
  13. 2026-06-23 04:51 UTCEG score recompute
  14. 2026-06-23 04:51 UTCGHSA enrichment
  15. 2026-06-22 14:25 UTCEPSS rescore
  16. 2026-06-22 05:51 UTCEG score recompute
  17. 2026-06-22 05:51 UTCGHSA enrichment
  18. 2026-06-21 14:56 UTCEPSS rescore
  19. 2026-06-21 02:58 UTCEG score recompute
  20. 2026-06-21 02:58 UTCGHSA enrichment
  21. 2026-06-21 01:59 UTCEPSS rescore
  22. 2026-06-20 02:55 UTCEG score recompute
  23. 2026-06-20 02:55 UTCGHSA enrichment
  24. 2026-06-19 19:26 UTCEPSS rescore
  25. 2026-06-19 01:39 UTCEG score recompute
  26. 2026-06-19 01:39 UTCGHSA enrichment
  27. 2026-06-18 17:52 UTCEPSS rescore
  28. 2026-06-18 02:23 UTCEG score recompute
  29. 2026-06-18 02:23 UTCGHSA enrichment
  30. 2026-06-17 17:53 UTCEPSS rescore
  31. 2026-06-17 03:27 UTCEG score recompute
  32. 2026-06-17 03:27 UTCGHSA enrichment
  33. 2026-06-16 17:53 UTCEPSS rescore
  34. 2026-06-16 04:31 UTCEG score recompute
  35. 2026-06-16 04:31 UTCGHSA enrichment
  36. 2026-06-15 17:49 UTCEPSS rescore
  37. 2026-06-15 05:28 UTCEG score recompute
  38. 2026-06-15 05:28 UTCGHSA enrichment
  39. 2026-06-14 23:18 UTCEPSS rescore
  40. 2026-06-14 06:33 UTCEG score recompute
  41. 2026-06-14 06:33 UTCGHSA enrichment
  42. 2026-06-13 23:00 UTCEPSS rescore
  43. 2026-06-13 07:37 UTCEG score recompute
  44. 2026-06-13 07:37 UTCGHSA enrichment
  45. 2026-06-12 23:12 UTCEPSS rescore
  46. 2026-06-12 23:12 UTCEPSS rescore
  47. 2026-06-12 08:39 UTCEG score recompute
  48. 2026-06-12 08:39 UTCGHSA enrichment
  49. 2026-06-11 14:00 UTCEPSS rescore
  50. 2026-06-11 09:43 UTCEG score recompute
  51. 2026-06-11 09:43 UTCGHSA enrichment
  52. 2026-06-10 22:19 UTCEPSS rescore
  53. 2026-06-10 13:22 UTCEPSS rescore
  54. 2026-06-10 10:48 UTCEG score recompute
  55. 2026-06-10 10:48 UTCGHSA enrichment
  56. 2026-06-09 11:52 UTCEG score recompute
  57. 2026-06-09 11:52 UTCGHSA enrichment
  58. 2026-06-08 12:57 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-9549?
CVE-2026-9549 is a medium vulnerability published on June 8, 2026. Stored cross-site scripting in the service discovery active check output in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can configure active or custom checks to inject malicious HTML or JavaScript into check output that executes in the browser of an…
When was CVE-2026-9549 disclosed?
CVE-2026-9549 was first published in the National Vulnerability Database on June 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9549 actively exploited?
CVE-2026-9549 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-9549?
CVE-2026-9549 has a CVSS v3 base score of 4.8 (NVD).
How do I remediate CVE-2026-9549?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-9549, 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

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