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

> Attackers can bypass redirect_uri validation to steal authorization codes, potentially leading to account takeover in Pocket ID deployments.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Mar 2026
- **Updated:** 10 Mar 2026
- **Also known as:** GHSA-9h33-g3ww-mqff, GO-2026-4653

## What is CVE-2026-28512?

CVE-2026-28512 is a high-severity vulnerability in pocket-id, published on 9 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-601 (URL Redirection to Untrusted Site)

## Which versions are affected by CVE-2026-28512?

3 open source packages ship an affected version, including github.com/pocket-id/pocket-id/backend. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/pocket-id/pocket-id/backend` | Go | All versions | 0.0.0-20260228130835-3a339e33191c |
| `github.com/pocket-id/pocket-id/backend` | Go | All versions | 0.0.0-20260228130835-3a339e33191c |
| `github.com/pocket-id/pocket-id/backend` | Go | All versions | 0.0.0-20260228130835-3a339e33191c |

Products: Pocket-Id Pocket Id.

## How do I fix CVE-2026-28512?

Upgrade github.com/pocket-id/pocket-id/backend to 0.0.0-20260228130835-3a339e33191c or later.

## Is CVE-2026-28512 being exploited?

There is no known exploitation of CVE-2026-28512 in the wild and no public exploit code.

## Other vulnerabilities in pocket-id

- [CVE-2026-43983](https://insights.sbomify.com/CVE-2026-43983/): Pocket ID: OIDC refresh token flow bypasses authorization revocation, account disabling, and group restrictions (high 8.5)
- [CVE-2026-28513](https://insights.sbomify.com/CVE-2026-28513/): Pocket ID: OIDC authorization code validation uses AND instead of OR, allowing cross-client token exchange (high 8.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28512 and fix it if it is affected.

What it is: CVE-2026-28512 is a high-severity vulnerability in pocket-id, published on 9 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-28512 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/pocket-id/pocket-id/backend (Go): affected all versions; fixed in 0.0.0-20260228130835-3a339e33191c
- github.com/pocket-id/pocket-id/backend (Go): affected all versions; fixed in 0.0.0-20260228130835-3a339e33191c
- github.com/pocket-id/pocket-id/backend (Go): affected all versions; fixed in 0.0.0-20260228130835-3a339e33191c

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-28512/ (Markdown: https://insights.sbomify.com/CVE-2026-28512/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28512
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28512
- OSV: https://osv.dev/vulnerability/CVE-2026-28512

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-28512/
Summaries are generated and may contain mistakes; the official description above is the record.