CVE-2026-76949
- Source
- https://cve.org/CVERecord?id=CVE-2026-76949
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-76949.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-76949
- Aliases
-
- EEF-CVE-2026-76949
- GHSA-hh34-374j-pfr5
- Published
- 2026-09-17T21:57:50Z
- Modified
- 2026-09-20T11:30:43Z
- Severity
-
- 9.1 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Remember-me sign-in guard reads a session key that is never written in ash_authentication, allowing session replacement
- Details
-
Authentication Bypass by Spoofing vulnerability in team-alembic ash_authentication allows an attacker who can plant a remember-me cookie in a victim's browser to replace that victim's authenticated session with one for the attacker's own account.
AshAuthentication.Plug.Helpers.sign_in_using_remember_me/3 skips re-authenticating an already-signed-in visitor by checking the session for "<subject_name>_token", but store_in_session/2 writes that key only when require_token_presence_for_authentication? is enabled and otherwise writes the bare subject name. At the default setting the guard therefore reads a key that is never written, its already-signed-in branch is unreachable, and the remember-me sign-in runs on every request through the per-request browser pipeline plug. A planted remember-me cookie is consequently honoured even for a visitor holding a live authenticated session, so whatever the victim enters afterwards lands in data the attacker controls. The read path in authenticate_resource_from_session/4 selects the key correctly, so the guard and the reader disagree about which key holds the session.
This issue affects ash_authentication: from 4.10.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.
- Database specific
{ "cna_assigner": "EEF", "cwe_ids": [ "CWE-290" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/76xxx/CVE-2026-76949.json", "unresolved_ranges": [ { "extracted_events": [ { "introduced": "3d3de314692558d06ec13945f857f00514e95a8c" }, { "fixed": "*" } ], "source": "AFFECTED_FIELD" } ] }- References
-
- https://cna.erlef.org/cves/CVE-2026-76949.html
- https://github.com
- https://osv.dev/vulnerability/EEF-CVE-2026-76949
- https://repo.hex.pm
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/76xxx/CVE-2026-76949.json
- https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-hh34-374j-pfr5
- https://nvd.nist.gov/vuln/detail/CVE-2026-76949
- https://github.com/team-alembic/ash_authentication/commit/3d3de314692558d06ec13945f857f00514e95a8c
- https://github.com/team-alembic/ash_authentication/commit/9a34136b844abe179da1075067cf2835c64dcc12
- https://github.com/team-alembic/ash_authentication/commit/b9568a53b438247238b1c5a4f49c8d84650f4bba
- https://github.com/team-alembic/ash_authentication
Affected packages
Git / github.com/team-alembic/ash_authentication
Affected ranges
- Type
- GIT
- Repo
- https://github.com/team-alembic/ash_authentication
- Events
-
IntroducedFixedIntroducedFixedFixedFixedFixed
- Database specific
-
Show details
{ "extracted_events": [ { "introduced": "4.10.0" }, { "fixed": "4.15.0" }, { "introduced": "5.0.0-rc.0" }, { "fixed": "5.0.0-rc.14" } ], "source": [ "DESCRIPTION", "REFERENCES" ] }