Pocket ID: OAuth redirect_uri validation bypass via userinfo/host confusion

CVE-2026-28512 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Impact

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.

Patches

Fixed in v2.3.1 (commit 3a339e33191c31b68bf57db907f800d9de5ffbc8).
The fix replaces delimiter-based callback matching with structured URL pattern matching and updates validation logic/tests.

Workarounds

  • Reject callback URLs containing userinfo (@) at reverse proxy / app policy level if feasible.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-03-09 17:24:27 UTC
Updated
2026-03-10 18:43:05 UTC
GitHub reviewed
2026-03-09 17:24:27 UTC
NVD published
2026-03-10

EPSS Score

Score Percentile
0.01% 2.95%

CVSS Scores

Base score Version Severity Vector
7.1 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

Type Value
GHSA GHSA-9h33-g3ww-mqff ↗
CVE CVE-2026-28512 ↗

CWEs

CWE id Name
CWE-601 URL Redirection to Untrusted Site ('Open Redirect')

Credits

  • ByamB4 (reporter)

Affected packages (1)

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

Ecosystem Package Vulnerable range First patched Vulnerable functions
go github.com/pocket-id/pocket-id/backend < 0.0.0-20260228130835-3a339e33191c 0.0.0-20260228130835-3a339e33191c —

References

cvelogic Threat Intelligence