How severe is CVE-2026-28512?

CVE-2026-28512 has a CVSS score of 7.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-28512?

CVE-2026-28512 affects the following packages: github.com/pocket-id/pocket-id/backend (Go). Ecosystems affected: Go.

How do I fix CVE-2026-28512?

Update github.com/pocket-id/pocket-id/backend to 0.0.0-20260228130835-3a339e33191c or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-28512 is resolved across your whole dependency graph.

How do I detect CVE-2026-28512 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/pocket-id/pocket-id/backend, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-28512 if there is no patch (or I can't update yet)?

Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.

Is CVE-2026-28512 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-28512 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-28512?

CVE-2026-28512 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 16th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-28512?

CVE-2026-28512 is classified as Open Redirect (CWE-601). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-28512 published, and has it been updated?

CVE-2026-28512 was published on March 9, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

HIGH severity

CVE-2026-28512 — backend

HIGHFix: pocket-id/pocket-id@3a339e3

CVE-2026-28512 is a high-severity (CVSS 7.1) Open Redirect vulnerability in github.com/pocket-id/pocket-id/backend. A fix is available for github.com/pocket-id/pocket-id/backend — see the affected versions and patch details below.

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

Also known asGHSA-9h33-g3ww-mqffGO-2026-4653

Published

Mar 9, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-28512.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk+0.02%

Lower risk than most CVEs16th percentile — riskier than 16% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐹github.com/pocket-id/pocket-id/backend

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/pocket-id/pocket-id/backend`	all versions	0.0.0-20260228130835-3a339e33191c`go get github.com/pocket-id/pocket-id/backend@v0.0.0-20260228130835-3a339e33191c`

Affected Products

1 product · 1 configurations

Application

pocket idpocket-id

≥ 2.0.0 && < 2.4.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/pocket-id/pocket-id/backend, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/pocket-id/pocket-id/backend to 0.0.0-20260228130835-3a339e33191c or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-28512 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.

Frequently Asked Questions

### 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 /