CVE-2026-25856: openbullet openbullet2 advisory

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

OpenBullet2 through version 0.3.2 contains an authenticated remote code execution vulnerability that allows authenticated users to execute arbitrary C# code on the server host by creating or modifying job configurations. Attackers can leverage the plain C# execution mode, which lacks reference filtering or API restrictions, to access the file system, spawn processes, and invoke arbitrary .NET APIs as the process user.

Description quoted from the CVE record (assigned by VulnCheck, published 2026-06-08).

Weakness: Improper Control of Generation of Code (‘Code Injection’)

How it can be exploited

Exploitable over the network with low attack complexity with no special attack requirements needing low privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CISA assessment (SSVC): CISA assesses that a public proof of concept exists. Automatable: no. Technical impact: total.

Public exploit evidence (Exploit Observer)

Exploit Observer found 1 Metasploit module naming this CVE.

Metasploit module

See all 4 references on Exploit Observer

Live scores

EPSS: 0.011
some chance of attack soon
VEDAS: 0.977
strong exploit evidence
On CISA KEV: Not listed
Detection rule: Suricata

Who is affected

Product	Affected	Not affected
openbullet openbullet2	up to and including 0.3.2	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

How to fix it

No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.

How to detect it

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-25856 OpenBullet2 - Remote Code Execution via C-Sharp Config Script. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-25856 OpenBullet2 - Remote Code Execution via C-Sharp Config Script"; flow:established,to_server; http.uri; content:"/api/v1/config"; nocase; fast_pattern; http.request_body; content:"cSharpScript"; nocase; classtype:web-application-attack; reference:cve,CVE-2026-25856; reference:url,https://www.exploit.observer/?keyword=CVE-2026-25856&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=openbullet2&match=exact; sid:1104203; rev:1;)

CVE-2026-25856.rules on GitHub

Advisories on this CVE

Rapid7 reports new Metasploit modules for Citrix NetScaler, Flowise, SPIP (full advisory)

References

Exploit code

https://hackernoon.com/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2 (technical-description, exploit)

Technical analysis and advisories

https://www.vulncheck.com/advisories/openbullet2-authenticated-rce-via-job-configuration-interface (third-party-advisory)

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.