# GHSA-74r7-3mjm-jc5v: eduMFA: Unauthenticated Failcounter Increment on Resolver Tokens via /validate/check

> Unauthenticated attackers can lock out all users in a resolver by incrementing failcounters via the validate endpoint, requiring an upgrade to fix.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 May 2026

## What is GHSA-74r7-3mjm-jc5v?

GHSA-74r7-3mjm-jc5v is a denial of service vulnerability in edumfa, published on 18 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

### Impact
If the resolver parameter is passed, but the user does not exist, all failcounters of tokens in that resolver will be increased.

### Patches
This, along with other issues, was fixed in eduMFA v2.9.1.

### Workarounds
Limiting access to `/validate/check` to client applications (i.e. Shibboleth/FreeRADIUS) using an authorization policy with `api_key_required` or using e.g. the reverse proxy.

## Which versions are affected by GHSA-74r7-3mjm-jc5v?

2 open source packages ship an affected version, including edumfa.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `edumfa` | PyPI | All versions | 2.9.1 |
| `edumfa` | PyPI | All versions | 2.9.1 |

## How do I fix GHSA-74r7-3mjm-jc5v?

Upgrade edumfa to 2.9.1 or later.

## Is GHSA-74r7-3mjm-jc5v being exploited?

There is no known exploitation of GHSA-74r7-3mjm-jc5v in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-74r7-3mjm-jc5v and fix it if it is affected.

What it is: GHSA-74r7-3mjm-jc5v is a denial of service vulnerability in edumfa, published on 18 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-74r7-3mjm-jc5v in the wild and no public exploit code.

Affected packages and fixed versions:
- edumfa (PyPI): affected all versions; fixed in 2.9.1
- edumfa (PyPI): affected all versions; fixed in 2.9.1

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/GHSA-74r7-3mjm-jc5v/ (Markdown: https://insights.sbomify.com/GHSA-74r7-3mjm-jc5v/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-74r7-3mjm-jc5v

---
From sbomify Insights: https://insights.sbomify.com/GHSA-74r7-3mjm-jc5v/
Summaries are generated and may contain mistakes; the official description above is the record.