CVE Intelligence
Critical File handling

CVE-2026-56590 — HCL BigFix Service Management is affected by multiple security vulnerabilities.

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.

Published Sep 18, 2026 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: HCL

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.3% (30-day exploitation probability)+3
  • Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.29%
ahead of 20% of scored CVEs · Oct 14, 2026
Affects
HCL Software
HCL BigFix Service Management and 1 more
CVSS base
9.8
Critical · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (HCL Software HCL BigFix Service Management, Hcltech Bigfix Service Management).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
HCL Software HCL BigFix Service Management version v27 Vulnerable CVE Program (cve.org) e CISA ADP
Hcltech Bigfix Service Management version 23version 27 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
9.8 CVSS 3.1 Critical 3.9 5.9 nvd@nist.gov via NIST National Vulnerability Database
6.4 CVSS 3.1 Medium 1.2 5.2 psirt@hcl.com via NIST National Vulnerability Database
6.4 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
6.4 CVSS 3.1 Medium — — HCL via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)
Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 9.8 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-434 · Unrestricted Upload of File with Dangerous Type

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Monitor file creation in web directories and paths with traversal sequences (../).
web/proxy/WAF logsnetwork IDS/IPSfile integrity (FIM)endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · hcl software/hcl bigfix service management
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 14, 2026
  • Affected products added · hcltech/bigfix service management
    Oct 14, 2026 · NIST National Vulnerability Database
  • CVSS changed · 9.8
    Oct 14, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 14, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 14, 2026 · Alertas do Telegram
  • CVE published
    Sep 18, 2026 · HCL

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 14, 2026 – Oct 14, 2026
  • 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

3 on the record

Elsewhere on this site

HCL Software
every CVE for this vendor
File handling
same class
CWE-434
other pages naming this weakness

Related CVEs (same products)

  • Low CVE-2026-56596 HCL BigFix Service Management is affected by multiple security vulnerabilities. 9d
  • Medium CVE-2026-67171 HCL BigFix Service Management is affected by multiple security vulnerabilities. 14d
  • Low CVE-2026-67172 HCL BigFix Service Management is affected by multiple security vulnerabilities. 14d
  • Medium CVE-2025-31980 HCL BigFix Service Management is affected by multiple security vulnerabilities. 14d
  • Critical CVE-2026-21806 HCL BigFix Service Management was affected with Admin Session Concurrency vulnerability (CVE-2026-21806) 27d
  • Medium CVE-2026-56597 HCL BigFix Service Management is affected by multiple security vulnerabilities. 27d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-56590 is "HCL BigFix Service Management is affected by multiple security vulnerabilities.", rated Critical. It affects HCL BigFix Service Management (HCL Software); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 0.29% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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