CVE-2026-86522: Log injection via an unescaped password reset identity in AshAuthentication

Severity: medium (CVSS 6.3 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-17 · updated 2026-09-18
Weakness: CWE-117

Description

Improper Output Neutralization for Logs vulnerability in team-alembic AshAuthentication allows an unauthenticated attacker to forge application log entries by submitting a password reset identity containing newlines or control characters. AshAuthentication.Strategy.Password.RequestPasswordReset.run/3 interpolates the identity argument, the email or username taken straight from the reset request, into its Logger.warning/1 heredocs without escaping, truncating or type-restricting it. The resource logged beside it is passed through inspect/1, which would have neutralized the value. A newline in the identity therefore ends the log record, and everything after it is written as a line of its own, so an attacker chooses the severity tag and the content of entries that appear to have come from the application. This issue affects ash_authentication: from 4.2.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.

Affected products

team-alembic ash_authentication: from 4.2.0 before 4.15.0; from 5.0.0-rc.0 before 5.0.0-rc.14 — fixed in 4.15.0, 5.0.0-rc.14

How to fix

Upgrade to a fixed version: team-alembic ash_authentication 4.15.0, 5.0.0-rc.14. Check the vendor advisory for mitigations.

References

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