# CVE-2026-4495: atjiu pybbs CommentApiController.java create cross site scripting

> Remote attackers can inject malicious scripts via the comment creation API in pybbs, potentially leading to code execution or account takeover.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/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:** A user has to click or open something
- **Fix available:** No
- **Published:** 20 Mar 2026
- **Updated:** 20 Mar 2026
- **Also known as:** GHSA-7r5p-f7h5-h6gp

## What is CVE-2026-4495?

CVE-2026-4495 is a medium-severity cross-site scripting vulnerability in atjiu pybbs, published on 20 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A security flaw has been discovered in atjiu pybbs 6.0.0. This impacts the function create of the file src/main/java/co/yiiu/pybbs/controller/api/CommentApiController.java. The manipulation results in cross site scripting. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-4495?


## How do I fix CVE-2026-4495?

No fix has been published for CVE-2026-4495 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4495 being exploited?

There is no known exploitation of CVE-2026-4495 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4495 and fix it if it is affected.

What it is: CVE-2026-4495 is a medium-severity cross-site scripting vulnerability in atjiu pybbs, published on 20 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-4495 in the wild and no public exploit code.

Affected product: atjiu pybbs. 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-2026-4495/ (Markdown: https://insights.sbomify.com/CVE-2026-4495/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4495
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4495
- OSV: https://osv.dev/vulnerability/CVE-2026-4495

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4495/
Summaries are generated and may contain mistakes; the official description above is the record.