Improper Authentication in AshAuthentication by Team Alembic
CVE-2026-65633

7.6HIGH

Key Information:

Vendor

Team-alembic

Status
Ash Authentication
Vendor
CVE Published:
25 August 2026

What is CVE-2026-65633?

An improper authentication flaw in AshAuthentication allows attackers to exploit the library's JWT handling. When tokens are issued for limited purposes, such as sign-in, they can be misused as general bearer tokens without proper validation checks. This vulnerability occurs due to a lack of verification of the token's purpose claim when certain configurations are set by the host application. Attackers can leverage exposed sign-in tokens obtained through various means, bypassing intended security protocols and authenticating as target users. Affected versions include ash_authentication from 3.10.5 to below 4.14.2 and from 5.0.0-rc.0 to below 5.0.0-rc.13.

Affected Version(s)

ash_authentication 3.10.5 < 4.14.2

ash_authentication 5.0.0-rc.0 < 5.0.0-rc.13

ash_authentication eca8cadea0f1595ed2c10a0c177b1da9aa9e5269

References

https://github.com/team-alembic/ash_authentication/securi...
vendor-advisoryrelated
https://cna.erlef.org/cves/CVE-2026-65633.html
related
https://osv.dev/vulnerability/EEF-CVE-2026-65633
related

CVSS V4

Score:
7.6
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

EQSTLab
James Harton
Jonatan Männchen / EEF
.