CVE-2026-8833

MEDIUMNVD 5.45.4—
EchelonGraph scoreHIGH confidence

Score 5.4 from GitHub Security Advisory (severity: HIGH) published 2026-06-08. NVD baseline CVSS 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
5.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.4Exploit: NoneExposed: 0

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

Improper neutralization of HTML-encoded characters in the URL validation function in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an authenticated user to bypass URL validation and inject malicious URLs such as javascript: URIs, resulting in cross-site scripting when another user interacts with the crafted link.

CVSS v3
5.4
EG Score
5.4(high)
EPSS
3.8%
KEV
Not listed

Published

June 8, 2026

Last Modified

June 9, 2026

Advisory Details (1)

Auto-updated Jun 9, 2026
No patch confirmed yet.
generic

Werk #20002: XSS in urls

https://checkmk.com/werk/20002

Vendor Advisories for CVE-2026-8833(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 20× in last 7d / 88× 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 16:27 UTCEPSS rescore
  3. 2026-07-05 20:30 UTCEG score recompute
  4. 2026-07-05 20:30 UTCGHSA enrichment
  5. 2026-07-05 02:31 UTCEPSS rescore
  6. 2026-07-05 02:30 UTCEPSS rescore
  7. 2026-07-04 20:16 UTCEG score recompute
  8. 2026-07-04 20:16 UTCGHSA enrichment
  9. 2026-07-04 06:31 UTCEPSS rescore
  10. 2026-07-04 06:31 UTCEPSS rescore
  11. 2026-07-03 19:57 UTCEG score recompute
  12. 2026-07-03 19:57 UTCGHSA enrichment
  13. 2026-07-02 19:48 UTCEG score recompute
  14. 2026-07-02 19:48 UTCGHSA enrichment
  15. 2026-07-01 19:36 UTCEG score recompute
  16. 2026-07-01 19:36 UTCGHSA enrichment
  17. 2026-07-01 15:07 UTCEPSS rescore
  18. 2026-06-30 23:22 UTCEPSS rescore
  19. 2026-06-30 19:27 UTCEG score recompute
  20. 2026-06-30 19:27 UTCGHSA enrichment
  21. 2026-06-29 19:17 UTCEG score recompute
  22. 2026-06-29 19:17 UTCGHSA enrichment
  23. 2026-06-29 14:06 UTCEPSS rescore
  24. 2026-06-28 17:08 UTCEG score recompute
  25. 2026-06-28 17:08 UTCGHSA enrichment
Show 63 more
  1. 2026-06-28 14:07 UTCEPSS rescore
  2. 2026-06-28 04:56 UTCEPSS rescore
  3. 2026-06-27 16:58 UTCEG score recompute
  4. 2026-06-27 16:57 UTCGHSA enrichment
  5. 2026-06-27 03:08 UTCEPSS rescore
  6. 2026-06-26 16:47 UTCEG score recompute
  7. 2026-06-26 16:47 UTCGHSA enrichment
  8. 2026-06-25 16:38 UTCEG score recompute
  9. 2026-06-25 16:38 UTCGHSA enrichment
  10. 2026-06-25 13:50 UTCEPSS rescore
  11. 2026-06-24 16:28 UTCEG score recompute
  12. 2026-06-24 16:28 UTCGHSA enrichment
  13. 2026-06-24 14:05 UTCEPSS rescore
  14. 2026-06-23 21:33 UTCEPSS rescore
  15. 2026-06-23 16:17 UTCEG score recompute
  16. 2026-06-23 16:17 UTCGHSA enrichment
  17. 2026-06-22 14:25 UTCEPSS rescore
  18. 2026-06-22 05:51 UTCEG score recompute
  19. 2026-06-22 05:51 UTCGHSA enrichment
  20. 2026-06-21 14:56 UTCEPSS rescore
  21. 2026-06-21 03:16 UTCEG score recompute
  22. 2026-06-21 03:16 UTCGHSA enrichment
  23. 2026-06-21 01:59 UTCEPSS rescore
  24. 2026-06-20 02:58 UTCEG score recompute
  25. 2026-06-20 02:57 UTCGHSA enrichment
  26. 2026-06-19 19:26 UTCEPSS rescore
  27. 2026-06-19 01:39 UTCEG score recompute
  28. 2026-06-19 01:39 UTCGHSA enrichment
  29. 2026-06-18 01:06 UTCEG score recompute
  30. 2026-06-18 01:06 UTCGHSA enrichment
  31. 2026-06-17 17:53 UTCEPSS rescore
  32. 2026-06-17 00:57 UTCEG score recompute
  33. 2026-06-17 00:57 UTCGHSA enrichment
  34. 2026-06-16 17:53 UTCEPSS rescore
  35. 2026-06-16 00:48 UTCEG score recompute
  36. 2026-06-16 00:48 UTCGHSA enrichment
  37. 2026-06-15 17:49 UTCEPSS rescore
  38. 2026-06-15 17:49 UTCEPSS rescore
  39. 2026-06-15 00:38 UTCEG score recompute
  40. 2026-06-15 00:38 UTCGHSA enrichment
  41. 2026-06-14 23:18 UTCEPSS rescore
  42. 2026-06-14 00:29 UTCEG score recompute
  43. 2026-06-14 00:29 UTCGHSA enrichment
  44. 2026-06-13 23:00 UTCEPSS rescore
  45. 2026-06-13 00:19 UTCEG score recompute
  46. 2026-06-13 00:19 UTCGHSA enrichment
  47. 2026-06-12 23:12 UTCEPSS rescore
  48. 2026-06-12 23:12 UTCEPSS rescore
  49. 2026-06-12 00:05 UTCEG score recompute
  50. 2026-06-12 00:05 UTCGHSA enrichment
  51. 2026-06-11 14:00 UTCEPSS rescore
  52. 2026-06-10 23:56 UTCEG score recompute
  53. 2026-06-10 23:56 UTCGHSA enrichment
  54. 2026-06-10 22:19 UTCEPSS rescore
  55. 2026-06-10 13:22 UTCEPSS rescore
  56. 2026-06-09 23:47 UTCEG score recompute▼ 3.10
  57. 2026-06-09 23:47 UTCGHSA enrichment
  58. 2026-06-09 15:17 UTCNVD updateCVSS v3 → 5.4 · severity → MEDIUM
  59. 2026-06-09 12:10 UTCEG score recompute
  60. 2026-06-09 12:10 UTCGHSA enrichment
  61. 2026-06-09 00:34 UTCEG score recompute
  62. 2026-06-09 00:34 UTCGHSA enrichment
  63. 2026-06-08 12:57 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-8833?
CVE-2026-8833 is a medium vulnerability published on June 8, 2026. Improper neutralization of HTML-encoded characters in the URL validation function in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an authenticated user to bypass URL validation and inject malicious URLs such as javascript: URIs, resulting in cross-site scripting when…
When was CVE-2026-8833 disclosed?
CVE-2026-8833 was first published in the National Vulnerability Database on June 8, 2026, with the most recent update on June 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8833 actively exploited?
CVE-2026-8833 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8833?
CVE-2026-8833 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-8833?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8833, 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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