Security readout for executives and security teams
Plain-English summary
A flaw in the YOOtheme Zoo extension for Joomla allows an unauthenticated remote attacker to upload arbitrary files by presenting them as images. Affected internet-facing sites could face severe confidentiality, integrity, and availability consequences. The supplied sources do not document what additional conditions determine the final impact after upload.
Executive priority
Treat as an immediate remediation priority for internet-facing systems. Identify affected Zoo installations, restrict vulnerable functionality, and upgrade promptly. Because the sources do not establish exploitation in the wild, communicate this as critical exposure reduction rather than a confirmed incident; investigate suspicious uploads separately.
Technical view
CVE-2026-74803 is a CWE-434 unrestricted file-upload vulnerability affecting Zoo versions 1.0.0 through 4.1.63. The image element trusts a client-supplied Content-Type within the image MIME group without adequately restricting the file itself. It carries CVSS 4.0 score 10.0, with network access, low complexity, no privileges, and no user interaction.
Likely exposure
Exposure exists where Joomla uses Zoo versions 1.0.0 through 4.1.63 and the vulnerable image element is remotely reachable. Internet-facing installations warrant immediate attention. The bundle provides no deployment prevalence, configuration prerequisites, or affected CPE identifiers, so organization-specific exposure requires inventory and route validation.
Exploitation context
The supplied record is not listed in KEV and provides no evidence of active exploitation, public proof-of-concept code, or observed attacks. That absence does not establish safety. Unauthenticated, low-complexity, network-accessible file upload is inherently high risk, particularly on publicly accessible Joomla sites.
Researcher notes
The record identifies MIME-group trust as the validation weakness but provides no code-level details, affected paths, configuration conditions, or post-upload execution behavior. CVSS indicates potential complete impact across vulnerable and subsequent systems, but those consequences should not be treated as universally demonstrated. Validate exposure safely without uploading executable content.
Mitigation direction
- Upgrade Zoo to version 4.1.64 or later after confirming current YOOtheme guidance.
- Temporarily restrict access to affected image-upload functionality until upgrading.
- Apply least-privilege permissions to upload directories and application processes.
- Review vendor guidance for any additional cleanup or configuration requirements.
Validation and detection
- Inventory Joomla sites and identify every installed Zoo version.
- Confirm affected sites no longer run Zoo versions 1.0.0 through 4.1.63.
- Determine whether the vulnerable image element is reachable without authentication.
- Review upload directories and logs for unexpected files or misleading image MIME declarations.
- After remediation, verify upload handling rejects files that are not valid permitted images.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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 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-2026-74803 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
- No
- 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
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.
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——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
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.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://www.yootheme.com/CVE reference, Joomla · product
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.