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Vulnerabilities

Vulnerability · CVE-2018-15919

Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use.

Published Aug 28, 2018 · catalog updated Jun 17, 2026 · Remotely observable behaviour in

Last checked Nov 4, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2018-15919. EPSS is 3.51%. Act only if a listed version of Remotely observable behaviour in is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Remotely observable behaviour in).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium5.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
3.51%
Remediation
Version ranges on file
Affected products
cpe netapp/cloud backup · cpe netapp/cn1610 firmware · cpe netapp/data ontap edge · cpe netapp/ontap select deploy · cpe netapp/steelstore · cpe openbsd/openssh

Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. NOTE: the discoverer states 'We understand that the OpenSSH developers do not want to treat such a username enumeration (or "oracle") as a vulnerability.'

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe netapp/cloud backupversion unspecified
  • cpe netapp/cn1610 firmwareversion unspecified
  • cpe netapp/data ontap edgeversion unspecified
  • cpe netapp/ontap select deployversion unspecified
  • cpe netapp/steelstoreversion unspecified
  • cpe openbsd/openssh>= 5.9, <= 7.8

How to fix CVE-2018-15919

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2018-15919. EPSS is 3.51%. Act only if a listed version of Remotely observable behaviour in is installed.

Which versions are affected?

Compare what you have installed with >= 5.9, <= 7.8. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-200: Exposure of Sensitive Information. EPSS 3.51%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

OpenSSH security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 28, 2018 · Monitored products — critical

    Detected

    Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. NOTE: the discoverer states 'We understand that the OpenSSH developers do not want to treat such a username enumeration (or "oracle") as a vulnerability.'

  2. Jun 17, 2026 · Monitored products — critical

    Updated

    Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. NOTE: the discoverer states 'We understand that the OpenSSH developers do not want to treat such a username enumeration (or "oracle") as a vulnerability.'

Sources

  • CVE.orgVulnerability recordCVE-2018-15919

    Official CVE identifier

    cve.org
  • Monitored products — criticalVendor advisoryCVE-2018-15919

    Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. NOTE: the discoverer states 'We understand that the OpenSSH developers do not want to treat such a username enumeration (or "oracle") as a vulnerability.'

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgNov 4, 2026
  • Monitored products — criticalNov 4, 2026