CVE-2026-55834 — MEDIUM (4.3)

Vulnerability Description

Pocket ID is an OIDC provider that allows users to authenticate with their passkeys to services. From 2.6.0 until 2.9.0, frontend/src/routes/authorize/+page.ts reads the redirect_uri query parameter and frontend/src/routes/authorize/+page.svelte uses the raw callbackURL in redirectWithError when prompt=none cannot complete silent authorization. The client-side path only blocks javascript and data schemes and does not invoke the backend callback allow-list validation, so an unauthenticated attacker who knows a valid client_id can redirect a victim browser to an arbitrary HTTP or HTTPS origin for phishing or OIDC error and state smuggling. This issue is fixed in version 2.9.0.

CVSS Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-601

References

FAQ

What is CVE-2026-55834?

CVE-2026-55834 is a vulnerability with a CVSS score of 4.3 (MEDIUM). Pocket ID is an OIDC provider that allows users to authenticate with their passkeys to services. From 2.6.0 until 2.9.0, frontend/src/routes/authorize/+page.ts reads the redirect_uri query parameter a...

How severe is CVE-2026-55834?

CVE-2026-55834 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-55834?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.