CVE-2026-81632 team-alembic CVE debrief

Who should care

Defenders responsible for AshAuthenticationPhoenix deployments, especially those with exposure to access logs, proxy logs, or browser history, should assess their exposure and prioritize verification and remediation.

Why it matters

CVE-2026-81632 allows recovery of single-use sign-in tokens from logs or browser history, potentially leading to unauthorized authentication. Defenders should verify exposure, prioritize remediation, and monitor for suspicious activity in AshAuthenticationPhoenix deployments.

• Recovery of single-use sign-in tokens from access logs, proxy logs, or browser history
• Potential authentication as the token owner
• Need for verification of exposure in AshAuthenticationPhoenix deployments
• Prioritization of remediation based on deployment context

Technical summary

The AshAuthenticationPhoenix library uses a single-use sign-in token as a query parameter in a GET request, which can be recorded in access logs, proxy logs, and browser history. This allows an attacker with access to these logs or history to recover the token and authenticate as its owner. The issue affects ash_authentication_phoenix: from 1.7.0 before 2.17.4 and from 3.0.0-rc.0 before 3.0.0-rc.11; ash_authentication: from 3.10.5 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14. The vulnerability can be mitigated by verifying exposure in AshAuthenticationPhoenix deployments, reviewing access logs, proxy logs, and browser history for potential token exposure, and considering an upgrade to a fixed version of

Defensive priority

Defenders should prioritize verifying exposure in AshAuthenticationPhoenix deployments, especially where access logs, proxy logs, or browser history may be accessible to unauthorized parties.

Recommended defensive actions

• Verify exposure in AshAuthenticationPhoenix deployments
• Review access logs, proxy logs, and browser history for potential token exposure
• Consider upgrading to a fixed version of AshAuthenticationPhoenix
• Monitor for suspicious activity related to sign-in tokens
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and source references provide details on the vulnerability in AshAuthenticationPhoenix, which allows recovery of a single-use sign-in token from access logs, proxy logs, or browser history.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.