CyberSecBulletin
CVE-2026-56590NVD status: Analyzed

HCL BigFix Service Management: Unrestricted Upload of File with Dangerous Type

CVE-2026-56590 is a critical-severity unrestricted upload of file with dangerous type vulnerability in HCL BigFix Service Management from HCL Software, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected HCL BigFix Service Management versions: v27. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of HCL BigFix Service Management you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on support.hcl-software.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
HCL SoftwareHCL BigFix Service Managementv27Not stated
HCL SoftwareBigfix Service Management23; 27Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.16.4MediumCNA (hcl.com)
CVSS 3.19.8CriticalNVD

Official description

HCL BigFix Service Management is affected by an Unrestricted File Upload vulnerability due to improper file validation controls, which could allow an unauthenticated attacker to upload and execute malicious payloads, resulting in a complete server compromise.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Unrestricted Upload of File with Dangerous Type

The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

How developers prevent this class of flaw

  • Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
  • When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
  • Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.

More Unrestricted Upload of File with Dangerous Type vulnerabilities (CWE-434)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in HCL BigFix Service Management

All HCL BigFix Service Management vulnerabilities

Recent Unrestricted Upload of File with Dangerous Type vulnerabilities

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