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No exploitation reported

CVE-2016-6474

No exploitation reported by the sources we read.

  • Published2016-12-14
  • WeaknessCWE-287

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability in the implementation of X.509 Version 3 for SSH authentication functionality in Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to bypass authentication on an affected system. More Information: CSCuv89417. Known Affected Releases: 15.5(2.25)T. Known Fixed Releases: 15.2(4)E1 15.2(4)E2 15.2(4)E3 15.2(4)EA4 15.2(4.0r)EB 15.2(4.1.27)EB 15.2(4.4.2)EA4 15.2(4.7.1)EC 15.2(4.7.2)EC 15.2(5.1.1)E 15.2(5.5.63)E 15.2(5.5.64)E 15.4(1)IA1.80 15.5(3)M1.1 15.5(3)M2 15.5(3)S1.4 15.5(3)S2 15.6(0.22)S0.12 15.6(1)T0.1 15.6(1)T1 15.6(1.15)T 15.6(1.17)S0.7 15.6(1.17)SP 15.6(1.22.1a)T0 15.6(2)S 15.6(2)SP 16.1(1.24) 16.1.2 16.2(0.247) 16.3(0.11) 3.8(1)E Denali-16.1.2.

Timeline

dates in UTC
  1. 2016-12-1400:59CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2016-6474?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-6474?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Cisco ios
BranchAffectedFixed in
15.5= 15.5\(2.25\)tno fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.07.3read 2026-10-23
  • NVDCVSS 2.05.8read 2026-10-23
  • NVDweakness (CWE)CWE-287read 2026-10-23
  • FIRST EPSSEPSS score1.4 %2026-10-23

Technical details

CVSS v3 Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Published
2016-12-14
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2016-6474?

A vulnerability in the implementation of X.509 Version 3 for SSH authentication functionality in Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to bypass authentication on an affected system. More Information: CSCuv89417. Known Affected Releases: 15.5(2.25)T. Known Fixed Releases: 15.2(4)E1 15.2(4)E2 15.2(4)E3 15.2(4)EA4 15.2(4.0r)EB 15.2(4.1.27)EB 15.2(4.4.2)EA4 15.2(4.7.1)EC 15.2(4.7.2)EC 15.2(5.1.1)E 15.2(5.5.63)E 15.2(5.5.64)E 15.4(1)IA1.80 15.5(3)M1.1 15.5(3)M2 15.5(3)S1.4 15.5(3)S2 15.6(0.22)S0.12 15.6(1)T0.1 15.6(1)T1 15.6(1.15)T 15.6(1.17)S0.7 15.6(1.17)SP 15.6(1.22.1a)T0 15.6(2)S 15.6(2)SP 16.1(1.24) 16.1.2 16.2(0.247) 16.3(0.11) 3.8(1)E Denali-16.1.2.

Is CVE-2016-6474 actively exploited?

Active exploitation of CVE-2016-6474 has not been confirmed. Its EPSS score was 1.4% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-6474?

CVE-2016-6474 has a CVSS v3 base score of 7.3 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

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