BeyondTrust Remote Support(RS) & Privileged Remote Access(PRA): OS Command Injection (CVE-2026-1731)
Published In CISA KEV since Sources: CVE.org
What is affected, what to do
BeyondTrust Remote Support (RS) and certain older versions of Privileged Remote Access (PRA) contain a critical pre-authentication remote code execution vulnerability. By sending specially crafted requests, an unauthenticated remote attacker may be able to execute operating system commands in the context of the site user.
The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. Update BeyondTrust Privileged Remote Access to version 25.1, BeyondTrust Remote Support to version 25.3.2. Immediate actions, mitigation and detection rules are in the runbook below.
- Affected
- BeyondTrust Privileged Remote Access
lt *..25.1 - BeyondTrust Remote Support
lt *..25.3.2
- BeyondTrust Privileged Remote Access
- Fixed in
- BeyondTrust Privileged Remote Access
25.1 - BeyondTrust Remote Support
25.3.2
- BeyondTrust Privileged Remote Access
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Metrics
9.9
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v4
9.8
CVSS v3
Severity Critical on the scale from 0 to 10.
Source: CVE.org
92.5 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.83
Show all metrics
- Severity
- Critical
Priority score
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 268.58
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- actively exploited (KEV)Source: VulnCheck KEV (opens in a new tab)
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 9.9
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 9.8
CVSS v4
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 9.9
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 92.5 %
- High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 99.83
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- Actively exploited
- Published
In CISA KEV since
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossaryCWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-78
Response and mitigation
Why act now?
Prioritisation rationale
This flaw is network-reachable without authentication or user interaction. It hits exactly the systems that, by design, concentrate privileged remote access to internal infrastructure and stored administrator credentials. Exploitation likelihood is very high, placing it among the CVEs most likely to be exploited, and CISA flags known use in ransomware campaigns; the typical pattern is initial access through the appliance followed by lateral movement with Vault credentials. Treat every internet-exposed RS or PRA instance as an emergency change (top priority, remediation within hours), consider it potentially compromised until proven otherwise, and assess NIS2 incident-reporting obligations if you operate critical infrastructure.
Runbook step 1
Immediate response (0-24 h)
- Patch now: Install the vendor security update on every on-prem BeyondTrust Remote Support (RS) and Privileged Remote Access (PRA) appliance, physical or virtual. A patch is available from the vendor — look up the exact version in the vendor advisory. Check older PRA releases specifically. If no direct patch path exists, upgrade to a supported release branch first.
- Confirm cloud instances: For SaaS instances, get written confirmation from the vendor or the support portal that the fix has been applied. Keep the confirmation as evidence for NIS2 documentation.
- Cut exposure: If you cannot patch within hours, restrict internet access to the appliance (TCP 443, and TCP 80 if open) at the perimeter firewall to known source ranges. If necessary, take the appliance offline temporarily. Losing remote-support capability is cheaper than losing your privileged access path.
- Check for compromise before declaring the appliance clean: If the appliance was reachable before patching, assume possible compromise. Preserve appliance logs, the syslog export and the configuration (users, API accounts, Jump Items, Vault entries) before rebooting or redeploying.
- Rotate secrets: On any suspicion of compromise, rotate local appliance admin accounts, API client secrets, privileged credentials stored in the PRA Vault, and LDAP/AD bind service accounts. With PRA, this directly affects domain and infrastructure accounts.
- Kill active sessions: Terminate live support and jump sessions and invalidate issued session keys.
Runbook step 2
Mitigation layers
- Network segmentation: Place the appliance in a dedicated DMZ. Allow egress only to defined destinations: Jump Clients, Jumpoints and vendor update servers. Block and log all other outbound traffic, especially direct internet egress and connections to domain controllers outside the defined ports.
- Admin surface restriction: Make the
/loginweb interface and/appliancemanagement reachable only from a management VLAN or via VPN with MFA. Publish only the endpoints that customer clients strictly require. - WAF/IPS: Front the appliance with a reverse proxy or WAF that blocks shell metacharacters in request parameters and WebSocket payloads:
;,|,`,$(,&&, and encoded forms such as%3Band%7C. Enable vendor IPS signatures for CVE-2026-1731 as soon as they ship. - IAM/least privilege: Enforce just-in-time access in PRA and configure automatic credential rotation after each use. Minimise standing domain-admin credentials in the Vault. Require approval workflows for sensitive jump targets.
- Logging: Forward appliance syslog to the SIEM. Set retention to cover NIS2 reporting deadlines and your internal forensic requirements.
Runbook step 3
Detection rules
- Web/proxy logs: Look for requests to the appliance containing shell metacharacters or encoded command fragments in the URI, parameters or WebSocket upgrade, e.g.
curl,wget,bash -c,/bin/sh,base64 -d. SPL sketch:index=proxy dest=<bt_appliance> (uri="*%3B*" OR uri="*%7C*" OR uri="*$(*" OR uri="*bash*" OR uri="*wget*") - Network telemetry (Zeek/Suricata/firewall): Flag new outbound connections from the appliance to unknown external IPs, unusual ports, or long-lived beacon-like flows. Zeek approach: filter
conn.logonid.orig_h == <appliance>with destinations outside the allowlist. Rare-domain DNS lookups from the appliance are also suspicious. - Appliance/syslog events: Watch for new local users or API accounts, group-permission changes, new Jump Items or Jumpoints, Vault exports, and configuration changes outside change windows. Sigma shape:
logsource: syslog, product: beyondtrust. Select on user/API creation event types and correlate with source IPs outside the admin network. - Downstream endpoints (Sysmon/EDR): Watch for off-hours sessions via BeyondTrust Jump Clients. Flag child processes of the BeyondTrust client such as
cmd.exe,powershell.exe,rundll32.exe(Sysmon EID 1). Also flag new services (Windows Event ID 7045) and Vault-account logons (Event ID 4624, logon type 3/10) immediately following jump sessions. - AD telemetry: Bulk LDAP queries or Kerberos service-ticket requests (Event ID 4769) by accounts that exist only in the PRA Vault indicate reuse of stolen credentials.
- Web/proxy logs: Look for requests to the appliance containing shell metacharacters or encoded command fragments in the URI, parameters or WebSocket upgrade, e.g.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
BeyondTrust Remote Support (RS) and certain older versions of Privileged Remote Access (PRA) contain a critical pre-authentication remote code execution vulnerability. By sending specially crafted requests, an unauthenticated remote attacker may be able to execute operating system commands in the context of the site user.
Source: NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| BeyondTrust | Remote Support(RS) & Privileged Remote Access(PRA) |
|
|
| beyondtrust | privileged_remote_access |
|
|
| beyondtrust | remote_support |
|
|
Weakness classes (CWE)
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Base
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
Entry at MITRE CWE-78
Public exploit references
Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.
| Source | Reference | Maturity | Published |
|---|---|---|---|
| CISA KEV Catalog | CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov | actively exploited (KEV) | |
| GitHub | win3zz/CVE-2026-1731 (opens in a new tab)github.com | PoC (publicly reported)reported, not verified | — |
| PoC-in-GitHub (nomi-sec) | CVE-2026-1731-BeyondTrust-RCE (opens in a new tab)github.com | PoC (publicly reported)reported, not verified |
References & sources
- beyondtrustcorp.service-now.comcsm?id=csm_kb_article&sysparm_article=KB0023293Permissions required
- beyondtrust.comtrust-center/security-advisories/bt26-02Vendor advisory
- github.comwin3zz/CVE-2026-1731Exploit, Exploit, Third-party advisory
- cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2026-1731government-resource, US government resource
- greynoise.ioblog/reconnaissance-beyondtrust-rce-cve-2026-1731Third-party advisory, Third-party advisory