CVE-2026-43634

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

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

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

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
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
EPSS PROB
0.4%
EPSS %ILE
27th
KEV
Not listed

Published

May 19, 2026

Last Modified

July 24, 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 / 24× 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 234 total refreshes for this CVE.

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

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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 on May 19, 2026, with the most recent update on July 24, 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 0.4% probability of exploitation in the next 30 days (27th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-43634?
CVE-2026-43634 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-43634?
A fix for CVE-2026-43634 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-43634 are linked in the Vendor Advisories panel on this page.

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