Answer in brief
CVE-2026-86688 records a High severity (CVSS 7.4) vulnerability in Session id is not renewed on authentication in ash_authentication, allowing session fixation. The current sources do not mark it as known exploited. The current feed maps team-alembic/ash_authentication (generic), team-alembic/ash_authentication (generic), team-alembic/team-alembic/ash_authentication (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps team-alembic/ash_authentication (generic), team-alembic/ash_authentication (generic), team-alembic/team-alembic/ash_authentication (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| team-alembic/ash_authenticationgeneric | >=a939dde9b917c072cdf10c4b0913a9886a4b0231 <* | * |
| team-alembic/ash_authenticationgeneric | >=0.2.0 <4.15.0 || >=5.0.0-rc.0 <5.0.0-rc.14 | 4.15.0, 5.0.0-rc.14 |
| team-alembic/team-alembic/ash_authenticationgeneric | >=a939dde9b917c072cdf10c4b0913a9886a4b0231 <* | * |
Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 17, 2026
Session Fixation vulnerability in team-alembic ash_authentication allows an attacker who can plant a session identifier in a victim's browser to hold an authenticated session once that victim signs in. AshAuthentication.Plug.Helpers.store_in_session/2 writes the authenticated subject into the existing session with Plug.Conn.put_session/3 and never calls Plug.Conn.configure_session(renew: true), so the identifier the visitor arrived with carries into their authenticated session. Every authentication event reaches this one function: the default success/4 injected by AshAuthentication.Phoenix.Controller.__using__/1, the AuthController emitted by mix ash_authentication_phoenix.install, and remember-me auto-login. AshAuthentication.Phoenix.Plug.store_in_session/2 is a defdelegate to it. Logout does not close the window either, because clear_session/2 ends with Plug.Conn.clear_session/1, which clears session contents but leaves the identifier intact, so a planted identifier survives a logout-then-login cycle. This issue affects ash_authentication: from 0.2.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.
Quoted source text, attributed separately from HOL analysis.