# CVE-2026-117470: WebAuthn assertion replay permits second-factor bypass in Psono Server


- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 27 Oct 2026
- **Updated:** 27 Oct 2026
- **Also known as:** GHSA-3gq2-hx4p-69qc

## What is CVE-2026-117470?

CVE-2026-117470 is a medium-severity vulnerability in esaqa GmbH Psono, published on 27 Oct 2026. 

### Official description

Psono Server CE & EE versions 3.1.0 through 7.2.3 did not consume a stored WebAuthn challenge after assertion verification. An unauthenticated remote attacker who possessed the user's password and one captured valid WebAuthn assertion could replay that assertion with separate login tokens while the stored challenge remained unchanged, bypassing the WebAuthn second factor. The attack required capture of a valid assertion and did not itself disclose plaintext secrets.

Weakness: CWE-294 (Authentication Bypass by Capture-replay)

## Which versions are affected by CVE-2026-117470?


## How do I fix CVE-2026-117470?

No fix has been published for CVE-2026-117470 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-117470 being exploited?

There is no known exploitation of CVE-2026-117470 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-117470 and fix it if it is affected.

What it is: CVE-2026-117470 is a medium-severity vulnerability in esaqa GmbH Psono, published on 27 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-117470 in the wild and no public exploit code.

Affected product: esaqa GmbH Psono. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-117470/ (Markdown: https://insights.sbomify.com/CVE-2026-117470/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-117470
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-117470
- OSV: https://osv.dev/vulnerability/CVE-2026-117470

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-117470/
Summaries are generated and may contain mistakes; the official description above is the record.