# CVE-2026-92288: Lemonldap::NG::Portal versions from 2.20.0 before 2.21.6, from 2.22.0 before 2.23.4 for Perl allow unauthenticated OAuth2 token introspectio

> Unauthenticated attackers can introspect OAuth2 tokens and read metadata, including user identifiers, by bypassing client secret verification for public Relying Parties.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 25 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-92288, GHSA-pxfv-p3g7-3fw3, UBUNTU-CVE-2026-92288

## What is CVE-2026-92288?

CVE-2026-92288 is a critical authentication bypass vulnerability, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Lemonldap::NG::Portal versions from 2.20.0 before 2.21.6, from 2.22.0 before 2.23.4 for Perl allow unauthenticated OAuth2 token introspection because checkEndPointAuthenticationCredentials does not verify the client secret of a public Relying Party.

checkEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the authentication method deduced from the request, client_secret_basic or client_secret_post. introspection() rejects a caller only when that method is missing or none, so a request carrying a public client_id and an arbitrary or empty secret passes the endpoint's authentication check.

An attacker who holds an access token and knows the client_id of any public Relying Party can confirm the token is active and read its metadata, including scope, audience, expiry and the sub claim. The sub claim is computed with the calling Relying Party's user identifier attribute, so an attacker can translate a user identifier from one Relying Party to another, defeating per-client and pseudonymous identifiers.

Weakness: CWE-1390 (Weak Authentication)

## Which versions are affected by CVE-2026-92288?


## How do I fix CVE-2026-92288?

Upgrade to a fixed version.

## Is CVE-2026-92288 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-92288 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-92288 and fix it if it is affected.

What it is: CVE-2026-92288 is a critical authentication bypass vulnerability, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-92288 exists.

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-2026-92288/ (Markdown: https://insights.sbomify.com/CVE-2026-92288/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-92288
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-92288
- OSV: https://osv.dev/vulnerability/CVE-2026-92288

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-92288/
Summaries are generated and may contain mistakes; the official description above is the record.