CVE-2026-43634

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-05-19. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

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

HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
15.1%
KEV
Not listed

Published

May 19, 2026

Last Modified

May 19, 2026

Advisory Details (5)

Auto-updated Jun 9, 2026
Patch available. Sources: github_commit, github_pr.
generic

HestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP Header | Advisories | VulnCheck

https://www.vulncheck.com/advisories/hestiacp-ip-spoofing-via-cf-connecting-ip-header
generic

Unauthenticated RCE and IP Spoofing in HestiaCP | Mercury ISS

https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634
github_pr Patch Available

Stop trusting unauthenticated proxy headers

Patch available: hestiacp/hestiacp 1.9.6 (PR #5273 merged 2026-03-24)

https://github.com/hestiacp/hestiacp/pull/5273
generic

Security vulnerability in Hestia CP · Issue #5229 · hestiacp/hestiacp · GitHub

https://github.com/hestiacp/hestiacp/issues/5229
github_commit Patch Available

commit f381e294500f (hestiacp/hestiacp)

Patch available: hestiacp/hestiacp 1.9.6 (contains commit f381e294500f)

https://github.com/hestiacp/hestiacp/commit/f381e294500f671cf12716c638afd0bfde901f88

Vendor Advisories for CVE-2026-43634(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 7× in last 7d / 68× 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 146 total refreshes for this CVE.

  1. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-08 15:16 UTCEPSS rescore
  4. 2026-07-07 13:46 UTCEPSS rescore
  5. 2026-07-06 16:27 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 02:30 UTCEPSS rescore
  8. 2026-07-04 06:31 UTCEPSS rescore
  9. 2026-07-01 15:07 UTCEPSS rescore
  10. 2026-06-30 23:22 UTCEPSS rescore
  11. 2026-06-29 20:55 UTCEG score recompute
  12. 2026-06-29 20:55 UTCGHSA enrichment
  13. 2026-06-29 14:06 UTCEPSS rescore
  14. 2026-06-28 14:07 UTCEPSS rescore
  15. 2026-06-28 08:41 UTCEG score recompute
  16. 2026-06-28 08:41 UTCGHSA enrichment
  17. 2026-06-28 04:56 UTCEPSS rescore
  18. 2026-06-27 20:26 UTCEG score recompute
  19. 2026-06-27 20:26 UTCGHSA enrichment
  20. 2026-06-27 08:05 UTCEG score recompute
  21. 2026-06-27 08:05 UTCGHSA enrichment
  22. 2026-06-27 03:08 UTCEPSS rescore
  23. 2026-06-26 19:48 UTCEG score recompute
  24. 2026-06-26 19:48 UTCGHSA enrichment
  25. 2026-06-26 05:21 UTCEG score recompute
Show 75 more
  1. 2026-06-26 05:21 UTCGHSA enrichment
  2. 2026-06-25 17:06 UTCEG score recompute
  3. 2026-06-25 17:06 UTCGHSA enrichment
  4. 2026-06-25 13:49 UTCEPSS rescore
  5. 2026-06-25 13:49 UTCEPSS rescore
  6. 2026-06-24 14:05 UTCEPSS rescore
  7. 2026-06-23 21:33 UTCEPSS rescore
  8. 2026-06-22 14:25 UTCEPSS rescore
  9. 2026-06-22 14:25 UTCEPSS rescore
  10. 2026-06-21 14:56 UTCEPSS rescore
  11. 2026-06-21 14:56 UTCEPSS rescore
  12. 2026-06-21 01:59 UTCEPSS rescore
  13. 2026-06-19 19:25 UTCEPSS rescore
  14. 2026-06-18 17:52 UTCEPSS rescore
  15. 2026-06-18 17:52 UTCEPSS rescore
  16. 2026-06-18 00:03 UTCEG score recompute
  17. 2026-06-18 00:03 UTCGHSA enrichment
  18. 2026-06-17 17:53 UTCEPSS rescore
  19. 2026-06-17 11:46 UTCEG score recompute
  20. 2026-06-17 11:46 UTCGHSA enrichment
  21. 2026-06-16 21:06 UTCEG score recompute
  22. 2026-06-16 21:06 UTCGHSA enrichment
  23. 2026-06-16 17:52 UTCEPSS rescore
  24. 2026-06-16 04:57 UTCEG score recompute
  25. 2026-06-16 04:57 UTCGHSA enrichment
  26. 2026-06-15 17:49 UTCEPSS rescore
  27. 2026-06-15 16:25 UTCEG score recompute
  28. 2026-06-15 16:24 UTCGHSA enrichment
  29. 2026-06-15 03:20 UTCEG score recompute
  30. 2026-06-15 03:20 UTCGHSA enrichment
  31. 2026-06-14 15:05 UTCEG score recompute
  32. 2026-06-14 15:05 UTCGHSA enrichment
  33. 2026-06-14 02:50 UTCEG score recompute
  34. 2026-06-14 02:50 UTCGHSA enrichment
  35. 2026-06-13 23:00 UTCEPSS rescore
  36. 2026-06-13 14:35 UTCEG score recompute
  37. 2026-06-13 14:35 UTCGHSA enrichment
  38. 2026-06-12 23:12 UTCEPSS rescore
  39. 2026-06-12 23:12 UTCEPSS rescore
  40. 2026-06-12 23:02 UTCEG score recompute
  41. 2026-06-12 23:02 UTCGHSA enrichment
  42. 2026-06-12 10:46 UTCEG score recompute
  43. 2026-06-12 10:46 UTCGHSA enrichment
  44. 2026-06-11 22:32 UTCEG score recompute
  45. 2026-06-11 22:32 UTCGHSA enrichment
  46. 2026-06-11 14:00 UTCEPSS rescore
  47. 2026-06-11 10:17 UTCEG score recompute
  48. 2026-06-11 10:17 UTCGHSA enrichment
  49. 2026-06-10 22:18 UTCEPSS rescore
  50. 2026-06-10 22:02 UTCEG score recompute
  51. 2026-06-10 22:02 UTCGHSA enrichment
  52. 2026-06-10 13:22 UTCEPSS rescore
  53. 2026-06-10 13:22 UTCEPSS rescore
  54. 2026-06-10 09:48 UTCEG score recompute
  55. 2026-06-10 09:48 UTCGHSA enrichment
  56. 2026-06-09 21:33 UTCEG score recompute
  57. 2026-06-09 21:33 UTCGHSA enrichment
  58. 2026-06-09 09:03 UTCEG score recompute
  59. 2026-06-09 09:03 UTCGHSA enrichment
  60. 2026-06-08 20:48 UTCEG score recompute
  61. 2026-06-08 20:48 UTCGHSA enrichment
  62. 2026-06-08 14:17 UTCEPSS rescore
  63. 2026-06-08 14:17 UTCEPSS rescore
  64. 2026-06-08 08:33 UTCEG score recompute
  65. 2026-06-08 08:33 UTCGHSA enrichment
  66. 2026-06-07 20:19 UTCEG score recompute
  67. 2026-06-07 20:19 UTCGHSA enrichment
  68. 2026-06-07 15:25 UTCEPSS rescore
  69. 2026-06-07 15:25 UTCEPSS rescore
  70. 2026-06-07 08:04 UTCEG score recompute
  71. 2026-06-07 08:04 UTCGHSA enrichment
  72. 2026-06-06 19:50 UTCEG score recompute
  73. 2026-06-06 19:49 UTCGHSA enrichment
  74. 2026-06-06 13:47 UTCEPSS rescore
  75. 2026-06-06 13:47 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-43634?
CVE-2026-43634 is a high vulnerability published on May 19, 2026. HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's…
When was CVE-2026-43634 disclosed?
CVE-2026-43634 was first published in the National Vulnerability Database on May 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43634 actively exploited?
CVE-2026-43634 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 15.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43634?
CVE-2026-43634 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-43634?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43634, 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.

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