BeyondTrust Remote Support <= 26.2.3 - Origin Validation File Upload

Exploited in the wild. Listed by CISA on 2026-10-16; known to be used by ransomware.

criticalseverity

9.3CVSS score

79.5%likelihood of exploitation, next 30 days

100%of all CVEs are less likely

Readycheck to confirm it

The vulnerability exists within internal components of BeyondTrust’s Remote Support product. The components did not adequately validate the origin of the messages it received. Under the right conditions, this could allow an attacker to perform file operations on the appliance.

Impact

Attackers can perform unauthorized file operations on the appliance, potentially leading to data tampering or system compromise.

Fix

Apply the BT26-05-RS patch or upgrade to a fixed BeyondTrust Remote Support build. SaaS instances were patched by the vendor.

How to confirm it

Send: GET /get_rdf?comp=sdcust&locale_code=en-us
Positive when: contains "0 Successful" and "BRDF" and "Thank you for using BeyondTrust" AND compare_versions(version, '<= 26.2.3') AND status 200

Run it with nuclei: nuclei -id CVE-2026-102764 -u <target>

The full check

id: CVE-2026-102764

info:
  name: BeyondTrust Remote Support <= 26.2.3 - Origin Validation File Upload
  author: DhiyaneshDk
  severity: critical
  description: |
    The vulnerability exists within internal components of BeyondTrust’s Remote Support product. The components did not adequately validate the origin of the messages it received. Under the right conditions, this could allow an attacker to perform file operations on the appliance.
  impact: |
    Attackers can perform unauthorized file operations on the appliance, potentially leading to data tampering or system compromise.
  remediation: |
    Apply the BT26-05-RS patch or upgrade to a fixed BeyondTrust Remote Support build. SaaS instances were patched by the vendor.
  reference:
    - https://www.beyondtrust.com/trust-center/security-advisories/bt26-05
    - https://github.com/rapid7/metasploit-framework/pull/22083
    - https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-102764
    - https://nvd.nist.gov/vuln/detail/CVE-2026-102764
  classification:
    cvss-metrics: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
    cvss-score: 9.3
    cve-id: CVE-2026-102764
    epss-score: 0.77994
    epss-percentile: 0.99575
    cwe-id: CWE-290
  metadata:
    verified: true
    max-request: 1
    vendor: beyondtrust
    product: remote_support
    shodan-query: http.title:"BeyondTrust"
  tags: cve,cve2026,beyondtrust,rce,kev,vkev

http:
  - raw:
      - |
        GET /get_rdf?comp=sdcust&locale_code=en-us HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "0 Successful"
          - "BRDF"
          - "Thank you for using BeyondTrust"
        condition: and

      - type: dsl
        dsl:
          - "compare_versions(version, '<= 26.2.3')"

      - type: status
        status:
          - 200

    extractors:
      - type: regex
        name: version
        part: body
        group: 1
        regex:
          - '(?s)BRDF.{6}([0-9]+\.[0-9]+\.[0-9]+(?:\.[0-9]+)?)'

References

Use this check only on systems you are authorised to test. Where the data comes from