# CVE-2026-3813: opencc JFlow WF_CCForm.java Calculate injection

> Remote attackers can execute arbitrary code via injection in the Calculate function of JFlow's WF_CCForm.java, requiring immediate attention due to public exploits.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Mar 2026
- **Updated:** 10 Mar 2026
- **Also known as:** GHSA-f3jc-x246-gfjr

## What is CVE-2026-3813?

CVE-2026-3813 is a medium-severity code injection vulnerability in opencc JFlow, published on 9 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was identified in opencc JFlow up to 5badc00db382d7cb82dad231e6a866b18e0addfe. Affected by this vulnerability is the function Calculate of the file src/main/java/bp/wf/httphandler/WF_CCForm.java. Such manipulation leads to injection. The attack may be performed from remote. The exploit is publicly available and might be used. This product utilizes a rolling release system for continuous delivery, and as such, version information for affected or updated releases is not disclosed. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-77 (Improper Neutralization of Special Elements used in a Command), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), CWE-707 (Improper Neutralization)

## Which versions are affected by CVE-2026-3813?

It affects 1 product.


Products: Opencc Jflow.

## How do I fix CVE-2026-3813?

No fix has been published for CVE-2026-3813 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3813 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3813 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3813 and fix it if it is affected.

What it is: CVE-2026-3813 is a medium-severity code injection vulnerability in opencc JFlow, published on 9 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3813 exists.

Affected product: opencc JFlow. 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-2026-3813/ (Markdown: https://insights.sbomify.com/CVE-2026-3813/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3813
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3813
- OSV: https://osv.dev/vulnerability/CVE-2026-3813

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3813/
Summaries are generated and may contain mistakes; the official description above is the record.