The AuthKit Remix Library renders sensitive auth data in HTML

Description

Summary

Before 0.15.0, @workos-inc/authkit-remix returned sensitive authentication artifacts from the authkitLoader, specifically sealedSession and accessToken. Because these values were returned from the loader, they were embedded into the server-rendered HTML and became readable by any script with access to the page’s DOM (e.g., in the presence of XSS or a malicious browser extension).

  • Impact: Exposure of these secrets can lead to session hijacking and unauthorized API access.
  • Fix: Version 0.15.0 changes the default behavior so the loader no longer returns sealedSession/accessToken. A secure server-side mechanism is provided to fetch an access token when needed.

Patches

Patched in v0.15.0.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2025-08-08 17:08:46 UTC
Updated
2025-09-25 22:56:20 UTC
GitHub reviewed
2025-08-08 17:08:46 UTC
NVD published
2025-08-08

EPSS Score

Score Percentile
0.06% 18.53%

CVSS Scores

Base score Version Severity Vector
7.1 3.1
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.

Identifiers

CWEs

CWE id Name
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

Credits

  • cai0duque (analyst)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm @workos-inc/authkit-remix < 0.15.0 0.15.0

References

cvelogic Threat Intelligence