# CVE-2025-66635: Memory corruption in Web Config

> A logged-in user can trigger a stack-based buffer overflow in Epson Web Config to execute arbitrary code.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Dec 2025
- **Updated:** 22 Dec 2025
- **Also known as:** GHSA-3xxw-5cqg-mq5w

## What is CVE-2025-66635?

CVE-2025-66635 is a high-severity memory corruption vulnerability in SEIKO EPSON CORPORATION Web Config, published on 16 Dec 2025. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Stack-based buffer overflow vulnerability exists in SEIKO EPSON Web Config. Specially crafted data input by a logged-in user may execute arbitrary code. As for the details of the affected products and versions, see the information provided by the vendor under [References].

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2025-66635?


## How do I fix CVE-2025-66635?

No fix has been published for CVE-2025-66635 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-66635 being exploited?

There is no known exploitation of CVE-2025-66635 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-66635 and fix it if it is affected.

What it is: CVE-2025-66635 is a high-severity memory corruption vulnerability in SEIKO EPSON CORPORATION Web Config, published on 16 Dec 2025. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-66635 in the wild and no public exploit code.

Affected product: SEIKO EPSON CORPORATION Web Config. 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-2025-66635/ (Markdown: https://insights.sbomify.com/CVE-2025-66635/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-66635
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-66635
- OSV: https://osv.dev/vulnerability/CVE-2025-66635

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-66635/
Summaries are generated and may contain mistakes; the official description above is the record.