CVE-2026-39920
Raw vector
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-39920 is a critical-severity Initialization of a Resource with an Insecure Default (CWE-1188) vulnerability. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Default Accounts (T1078.001); ranked at the 43th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to CM-2 (Baseline Configuration) and CM-6 (Configuration Settings) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-39920 is a critical remote code execution vulnerability affecting BridgeHead FileStore versions prior to 24A, released in early 2024. The issue stems from the exposure of the Apache Axis2 administration module on network-accessible endpoints using default credentials. This configuration allows unauthenticated remote attackers to gain access and execute arbitrary operating system commands, as mapped to CWEs-1188 (Insecure Default Initialization of Resource) and CWE-1391 (Use of Weak Credentials). The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its network accessibility and lack of prerequisites.
Any unauthenticated attacker with network access to the affected BridgeHead FileStore instance can exploit this vulnerability. The attack begins with authenticating to the Axis2 admin console using the default credentials, followed by uploading a malicious Java archive (JAR) file as a web service. Once deployed, attackers send SOAP requests to the service to execute arbitrary OS commands on the host system, potentially leading to full compromise including data exfiltration, persistence, or lateral movement.
Advisories, including those from VulnCheck and BridgeHead Software, recommend upgrading to FileStore version 24A, which resolves the exposure of the Apache Axis2 admin module. Additional guidance from Apache Axis2 documentation and related JIRA issue AXIS2-4279 highlights securing or disabling the admin console to prevent default credential exploitation. A proof-of-concept exploit is available via a public GitHub Gist, underscoring the need for immediate patching.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-25569
Vulnerability Data
BridgeHead FileStore versions prior to 24A (released in early 2024) expose the Apache Axis2 administration module on network-accessible endpoints with default credentials that allows unauthenticated remote attackers to execute arbitrary OS commands. Attackers can authenticate to the admin console using…
more
default credentials, upload a malicious Java archive as a web service, and execute arbitrary commands on the host via SOAP requests to the deployed service.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 20 hardening rules · 8 OS baselines
V14.3.2V6.2.2V6.3.2V11.3.1
Mitigating Controls (NIST 800-53 r5) AI
IA-5 directly requires management of authenticator strength, distribution, and replacement, stopping default or guessable credentials from being introduced or used.
Baseline configuration directly requires documenting and maintaining secure initial settings instead of insecure defaults.
Configuration settings mandate the most restrictive values be applied at initialization, eliminating reliance on insecure factory defaults.
Least privilege reduces the blast radius of any insecure default permissions that remain after initialization.
Security engineering principles include explicit requirements for secure defaults during resource initialization and design.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Hardened baselines and configuration management directly replace insecure defaults with secure settings.
PR.AA-01's credential issuance and key-management processes directly block most weak/default credential usage, yet leave hard-coded or product-design instances of CWE-1391 only partially addressed.
Password-strength policies in PR.AA-03 directly block weak authenticators, but the control leaves hard-coded/default credentials largely unaddressed.
Secure development practices include designing products with secure defaults rather than insecure ones.
Pre-acquisition integrity checks can reject products known to ship with insecure defaults.
Training raises password-hygiene awareness and can therefore reduce some weak-credential mistakes, yet supplies no enforcement mechanism and leaves the dominant technical sources of CWE-1391 untouched.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Directly requires secure generation, distribution and storage of authentication credentials, eliminating default/hard-coded weak passwords.
Mandates secure authentication mechanisms that preclude use of weak or default credentials.
Secure-coding rules can prohibit hard-coded passwords, yet coverage depends on specific coding standards adopted.
Security testing can discover weak credentials, but does not guarantee they are prevented by design.
Mandating secure baseline templates and immediate replacement of vendor defaults directly stops systems from being deployed with insecure factory settings that attackers can exploit.
Restricts privileged accounts but does not explicitly address default or hard-coded credentials for those accounts.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (4 rules)
- V-248667 OL 8 must configure the use of the pam_faillock.so module in the /etc/pam.d/system-auth file. prevents CWE-1391
- V-248668 OL 8 must configure the use of the pam_faillock.so module in the /etc/pam.d/password-auth file. prevents CWE-1391
- V-248823 OL 8 must not have the telnet-server package installed. prevents CWE-1188
RHEL 7 (2 rules)
- V-204627 SNMP community strings on the Red Hat Enterprise Linux operating system must be changed from the default. prevents CWE-1188
- V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-1391
RHEL 8 (1 rule)
- V-244533 RHEL 8 must configure the use of the pam_faillock.so module in the /etc/pam.d/system-auth file. prevents CWE-1391
Ubuntu 22.04 (1 rule)
- V-260529 Ubuntu 22.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-1188
Ubuntu 24.04 (1 rule)
- V-270708 Ubuntu 24.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-1188
Windows Server 2016 (1 rule)
- V-224972 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-1188
Windows Server 2019 (1 rule)
- V-205741 Windows Server 2019 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-1188