Security readout for executives and security teams
Plain-English summary
Balbooa Forms versions 1.0 through 2.4.0 allow an unauthenticated attacker to upload executable files to a Joomla site. Successful exploitation can give the attacker full control of the server, exposing data, disrupting services, and enabling further compromise.
Executive priority
Treat as an emergency remediation item. The vulnerability requires no credentials, enables complete server compromise, carries a 10.0 score, and appears in CISA's Known Exploited Vulnerabilities catalog.
Technical view
CVE-2026-56291 is a CWE-434 unrestricted file-upload vulnerability in the Balbooa Forms Joomla extension. It is remotely exploitable without authentication or user interaction and can lead to arbitrary code execution. The supplied CVSS 4.0 score is 10.0.
Likely exposure
Internet-accessible Joomla sites running Balbooa Forms versions 1.0 through 2.4.0 are the primary exposure. The bundle identifies versions below 2.4.1 as vulnerable; it provides no evidence that Joomla sites without this extension are affected.
Exploitation context
CISA KEV inclusion supports that this vulnerability has been exploited in the wild. The supplied sources do not establish exploitation volume, targeted organizations, attacker identities, or specific indicators of compromise.
Researcher notes
The documented weakness is CWE-434. Exposure depends on extension presence, affected version, and network reachability. Investigation should focus on unauthorized uploads, executable content, web-root changes, and evidence of follow-on code execution. The bundle provides no vulnerability-specific indicators or forensic artifacts.
Mitigation direction
- Upgrade Balbooa Forms to version 2.4.1 or later after confirming current vendor guidance.
- Prioritize internet-facing and business-critical Joomla systems for immediate remediation.
- If immediate upgrading is impossible, disable the extension or restrict public access pending vendor-approved mitigation.
- Preserve relevant logs and investigate affected systems for prior compromise.
Validation and detection
- Inventory Joomla installations and record the installed Balbooa Forms version.
- Confirm no reachable system remains on versions 1.0 through 2.4.0.
- Review web, Joomla, and security logs for unexpected file uploads or subsequent execution.
- Inspect web-accessible directories for unauthorized executable files and unexplained modifications.
- Verify remediated sites operate correctly and remain protected after updating.
Public sources used
The source record changed after analysis: Material source record changed after analysis.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-56291 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 10 (4.0)
- Known Exploited
- Yes
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/AU:Y/U:Red
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/AU:Y/U:Red——JoomlaVulnerability scoring details
Base CVSS 4.0 score
10CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/AU:Y/U:Red
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- Added to KEVCISA-ADP
CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.
- ADP timelineCISA-ADP
CVE-2026-56291 added to CISA KEV
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-07-10T00:00:00.000Z: CVE-2026-56291 added to CISA KEV
Source materials
- CVE List V5 sourceCVE List V5
- https://www.balbooa.com/joomla-formsCVE reference, Joomla · product
- https://mysites.guru/blog/balbooa-forms-unauthenticated-file-upload-flaw/CVE reference, Joomla · third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56291CVE reference, CISA-ADP · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.