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Vulnerabilities

Vulnerability · CVE-2026-48859

Observable Timing Discrepancy vulnerability in Erlang/OTP ssh (ssh_auth, ssh_options modules) allows unauthenticated remote username enumeration via timing side-channe…

Published Jun 10, 2026 · catalog updated Nov 11, 2026 · the affected product

Last checked Nov 11, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-48859. EPSS is 0.35%. Act only if a listed version of the affected product is installed.

Gaps on this record

  • No plain product name is stored. The page cannot tell you which product to check.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium6.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.35%
Remediation
Version ranges on file
Affected products
cpe erlang/erlang/otp · cpe erlang/erlang/ssh

Observable Timing Discrepancy vulnerability in Erlang/OTP ssh (ssh_auth, ssh_options modules) allows unauthenticated remote username enumeration via timing side-channel in password authentication. When the SSH daemon is configured with the user_passwords or password option, ssh_auth:check_password/3 performs a PBKDF2-SHA256 computation with 600,000 iterations (~300ms) for valid usernames, but returns immediately (~0ms) for invalid usernames via the ssh_options:get_password_option/2 path. This timing difference is detectable in a single authentication attempt and allows an unauthenticated attacker to distinguish valid from invalid usernames. The user_passwords and password options are documented as intended for test purposes; the recommended alternative is pwdfun, which is not affected by this vulnerability. This vulnerability is associated with program files lib/ssh/src/ssh_auth.erl and lib/ssh/src/ssh_options.erl. This issue affects OTP from OTP 29.0 before OTP 29.0.2, corresponding to ssh from 6.0 before 6.0.1.

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 erlang/erlang/otp< 29.0.2
  • cpe erlang/erlang/ssh< 6.0.1

How to fix CVE-2026-48859

  • Upgrade

    CVE-2026-48859 lists a fix boundary at 29.0.2. Compare the installed build with that boundary before you change production.

  • Version check

    Affected < 29.0.2

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

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-2026-48859. EPSS is 0.35%. Act only if a listed version of the affected product is installed.

Which versions are affected?

Compare what you have installed with < 29.0.2, < 6.0.1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-208. EPSS 0.35%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

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

Timeline

Detection, updates, and resolution for this record.

  1. Jun 10, 2026 · NIST NVD

    Detected

    Observable Timing Discrepancy vulnerability in Erlang/OTP ssh (ssh_auth, ssh_options modules) allows unauthenticated remote username enumeration via timing side-channel in password authentication. When the SSH daemon is configured with the user_passwords or password option, ssh_auth:check_password/3 performs a PBKDF2-SHA256 computation with 600,000 iterations (~300ms) for valid usernames, but retu

  2. Nov 11, 2026 · NIST NVD

    Updated

    Observable Timing Discrepancy vulnerability in Erlang/OTP ssh (ssh_auth, ssh_options modules) allows unauthenticated remote username enumeration via timing side-channel in password authentication. When the SSH daemon is configured with the user_passwords or password option, ssh_auth:check_password/3 performs a PBKDF2-SHA256 computation with 600,000 iterations (~300ms) for valid usernames, but retu

Sources

  • CVE.orgVulnerability recordCVE-2026-48859

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-48859

    Observable Timing Discrepancy vulnerability in Erlang/OTP ssh (ssh_auth, ssh_options modules) allows unauthenticated remote username enumeration via timing side-channel in password authentication. When the SSH daemon is configured with the user_passwords or password option, ssh_

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 11, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgNov 11, 2026
  • NIST NVDNov 11, 2026