CVE-2016-8858

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2022-05-14. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
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: 29%CVSS: 7.5Exploit: Elevated riskExposed: 0

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

The kex_input_kexinit function in kex.c in OpenSSH 6.x and 7.x through 7.3 allows remote attackers to cause a denial of service (memory consumption) by sending many duplicate KEXINIT requests. NOTE: a third party reports that "OpenSSH upstream does not consider this as a security issue."

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Track)
EG Risk 65/100SSVC: 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
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
29%
EPSS %ILE
98%
KEV
Not listed

Published

December 9, 2016

Last Modified

June 17, 2026

References (26)

Vendor Advisories for CVE-2016-8858(1)

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

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
openssh—1:7.3p1-2—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
openssh—1:7.3p1-2—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
openssh—1:7.3p1-2—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
openssh—1:7.3p1-2—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 18× 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 129 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCdag-erling/kexkill
    First seen Nov 3, 2016

    Proof of concept for CVE-2016-8858

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2016-8858?
CVE-2016-8858 is a high vulnerability published on December 9, 2016. The kexinputkexinit function in kex.c in OpenSSH 6.x and 7.x through 7.3 allows remote attackers to cause a denial of service (memory consumption) by sending many duplicate KEXINIT requests. NOTE: a third party reports that "OpenSSH upstream does not consider this as a security issue."
When was CVE-2016-8858 disclosed?
CVE-2016-8858 was first published in the National Vulnerability Database on December 9, 2016, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-8858 actively exploited?
CVE-2016-8858 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 29% probability of exploitation in the next 30 days, which ranks it in the top 1.9% of all scored CVEs.
What is the CVSS score of CVE-2016-8858?
CVE-2016-8858 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2016-8858?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-8858, 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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