# CVE-2026-4958: OpenBMB XAgent WebSocket Endpoint replayer.py ReplayServer.send_data authorization

> Attackers can bypass authorization in the XAgent WebSocket endpoint by manipulating interaction_id, potentially accessing restricted replay data.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/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:** Not needed
- **Fix available:** No
- **Published:** 27 Mar 2026
- **Updated:** 30 Mar 2026
- **Also known as:** GHSA-pj48-vv9m-5qqf

## What is CVE-2026-4958?

CVE-2026-4958 is a low-severity missing authorization vulnerability in OpenBMB XAgent, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability has been found in OpenBMB XAgent 1.0.0. This affects the function ReplayServer.on_connect/ReplayServer.send_data of the file XAgentServer/application/websockets/replayer.py of the component WebSocket Endpoint. Such manipulation of the argument interaction_id leads to authorization bypass. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is reported as difficult. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key), CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-4958?

It affects 1 product.


Products: Openbmb Xagent.

## How do I fix CVE-2026-4958?

No fix has been published for CVE-2026-4958 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4958 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4958 exists.

## Other vulnerabilities in OpenBMB XAgent

- [CVE-2026-4959](https://insights.sbomify.com/CVE-2026-4959/): OpenBMB XAgent ShareServer WebSocket Endpoint share.py check_user missing authentication (medium 6.9)
- [CVE-2024-2007](https://insights.sbomify.com/CVE-2024-2007/): OpenBMB XAgent Privileged Mode sandbox (medium 5.3)
- [CVE-2026-4957](https://insights.sbomify.com/CVE-2026-4957/): OpenBMB XAgent API Key function_handler.py FunctionHandler.handle_tool_call log file (medium 5.1)
- [CVE-2025-6281](https://insights.sbomify.com/CVE-2025-6281/): OpenBMB XAgent community path traversal (medium 5.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4958 and fix it if it is affected.

What it is: CVE-2026-4958 is a low-severity missing authorization vulnerability in OpenBMB XAgent, published on 27 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-2026-4958 exists.

Affected product: OpenBMB XAgent. 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-2026-4958/ (Markdown: https://insights.sbomify.com/CVE-2026-4958/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4958
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4958
- OSV: https://osv.dev/vulnerability/CVE-2026-4958

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-4958/
Summaries are generated and may contain mistakes; the official description above is the record.