# CVE-2026-101100: ag-ui-protocol ag-ui Middleware filter-tool-calls.ts FilterToolCallsMiddleware cleanup

> Incomplete cleanup in FilterToolCallsMiddleware may allow remote attackers to access residual data or bypass intended filtering mechanisms.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X`)
- **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:** 28 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-3mm7-4jh6-p5gf

## What is CVE-2026-101100?

CVE-2026-101100 is a medium-severity vulnerability in ag-ui-protocol ag-ui, published on 28 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw has been found in ag-ui-protocol ag-ui up to 2026-09-07. This vulnerability affects the function FilterToolCallsMiddleware of the file sdks/typescript/packages/client/src/middleware/filter-tool-calls.ts of the component Middleware. Executing a manipulation can lead to incomplete cleanup. The attack may be launched remotely. Upgrading to version 2026-09-08 is able to resolve this issue. This patch is called c346119fe870b70f5c19738ee5119f3e1456e59d. It is suggested to upgrade the affected component.

Weakness: CWE-459 (Incomplete Cleanup)

## Which versions are affected by CVE-2026-101100?


## How do I fix CVE-2026-101100?

No fix has been published for CVE-2026-101100 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-101100 being exploited?

There is no known exploitation of CVE-2026-101100 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-101100 and fix it if it is affected.

What it is: CVE-2026-101100 is a medium-severity vulnerability in ag-ui-protocol ag-ui, published on 28 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-101100 in the wild and no public exploit code.

Affected product: ag-ui-protocol ag-ui. 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-2026-101100/ (Markdown: https://insights.sbomify.com/CVE-2026-101100/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-101100
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-101100
- OSV: https://osv.dev/vulnerability/CVE-2026-101100

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-101100/
Summaries are generated and may contain mistakes; the official description above is the record.