# GHSA-g588-cjg3-6g78: Steamworks game clients/servers using P2P authentication vulnerable to denial of service

> A malicious game client can cause a denial of service in Steamworks game clients or servers by sending a specific authentication ticket that triggers a panic.

- **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:** 5 May 2026
- **Also known as:** RUSTSEC-2026-0121

## What is GHSA-g588-cjg3-6g78?

GHSA-g588-cjg3-6g78 is a denial of service vulnerability in steamworks, published on 5 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Processing the raw `ValidateAuthTicketResponse_t` callback data panics when the `m_eAuthSessionResponse` field is `k_EAuthSessionResponseAuthTicketNetworkIdentityFailure`. This can lead to denial of service in game clients and servers using the `begin_authentication_session` API to authenticate players if a malicious game client sends an authentication ticket with a network identity that does not match that of the verifier.

## Which versions are affected by GHSA-g588-cjg3-6g78?

3 open source packages ship an affected version, including steamworks.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `steamworks` | crates.io | All versions | 0.13.1 |
| `steamworks` | crates.io | All versions | 0.13.1 |
| `steamworks` | crates.io | From 0.0.0-0 | 0.13.1 |

## How do I fix GHSA-g588-cjg3-6g78?

Upgrade steamworks to 0.13.1 or later.

## Is GHSA-g588-cjg3-6g78 being exploited?

There is no known exploitation of GHSA-g588-cjg3-6g78 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-g588-cjg3-6g78 and fix it if it is affected.

What it is: GHSA-g588-cjg3-6g78 is a denial of service vulnerability in steamworks, published on 5 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-g588-cjg3-6g78 in the wild and no public exploit code.

Affected packages and fixed versions:
- steamworks (crates.io): affected all versions; fixed in 0.13.1
- steamworks (crates.io): affected all versions; fixed in 0.13.1
- steamworks (crates.io): affected from 0.0.0-0; fixed in 0.13.1

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-g588-cjg3-6g78/ (Markdown: https://insights.sbomify.com/GHSA-g588-cjg3-6g78/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-g588-cjg3-6g78

---
From sbomify Insights: https://insights.sbomify.com/GHSA-g588-cjg3-6g78/
Summaries are generated and may contain mistakes; the official description above is the record.