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VulnerabilityPublished Updated

CVE-2026-48859: Erlang OTP · Timing Side Channel

Affects Erlang OTPSource CVE Database V5

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Not known to be exploited · CVSS 6.3 Medium : upgrade to 29.0.2 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score
6.3Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 29.0.2, 6.0.1, c342092ef4b369bb409d5b71ac8fd83bab74aedf
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade OTP to 29.0.2; OTP and ssh to 6.0.1; OTP to c342092ef4b369bb409d5b71ac8fd83bab74aedf.

Affected software

ProductAffectedFixed in
ErlangOTPAffected
  • >=29.0 <29.0.2
Fixed in
  • 29.0.2
ErlangOTPAffected
  • >=6.0 <6.0.1
Fixed in
  • 6.0.1
ErlangOTPAffected
  • ≥ 032d1bc9491a3975c68faf9bc7776115d6ae3005, < c342092ef4b369bb409d5b71ac8fd83bab74aedf
Fixed in
  • c342092ef4b369bb409d5b71ac8fd83bab74aedf
GitHubsshpkg:github/sshOther threatsAffected
  • >=6.0 <6.0.1
Fixed in
  • 6.0.1

CPE configurations (1)

  • cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The vulnerability affects OTP versions before 29.0.2 and SSH versions before 6.0.1. Users should upgrade to OTP 29.0.2 or later and SSH 6.0.1 or later once available. Alternatively, avoid using the user_passwords or password options for SSH authentication and switch to the recommended pwdfun option, which is not affected by this timing discrepancy.

Description

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.

References

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