# CVE-2026-90777: ESPnet before 202609 Remote Code Execution via Unsafe Deserialization

> Attackers can execute arbitrary code by supplying malicious model checkpoints to ESPnet due to unsafe deserialization practices.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-64f6-3gqc-r926, GHSA-r7rw-fc94-3p58

## What is CVE-2026-90777?

CVE-2026-90777 is a high-severity unsafe deserialization vulnerability in espnet, published on 13 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

ESPnet before 202609 deserializes pretrained model checkpoints using torch.load with weights_only=False, allowing arbitrary code execution from attacker-supplied files. Attackers can craft malicious checkpoint files that execute code during deserialization when loaded through the initialization or fine-tuning path.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-90777?


## How do I fix CVE-2026-90777?

No fix has been published for CVE-2026-90777 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90777 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90777 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90777 and fix it if it is affected.

What it is: CVE-2026-90777 is a high-severity unsafe deserialization vulnerability in espnet, published on 13 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90777 exists.

Affected product: espnet. 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-2026-90777/ (Markdown: https://insights.sbomify.com/CVE-2026-90777/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90777
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90777
- OSV: https://osv.dev/vulnerability/CVE-2026-90777

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90777/
Summaries are generated and may contain mistakes; the official description above is the record.