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PatchSiren cyber security CVE debrief

CVE-2026-48958 Joomla! Project CVE debrief

CVE-2026-48958 is a medium-severity vulnerability allowing unauthorized users to create custom fields via webservices endpoints due to an improper access check. The CVE record was published on 2026-07-07T19:16:54.567Z and has not been modified since then. This vulnerability affects Joomla installations and is classified under CWE-284, with a CVSS score of 6.4. Security teams and administrators should assess and mitigate this vulnerability to prevent unauthorized custom field creation.

Vendor
Joomla! Project
Product
Joomla! CMS
CVSS
MEDIUM 6.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-07
Original CVE updated
2026-07-09
Advisory published
2026-07-07
Advisory updated
2026-07-09

Who should care

Security teams and administrators of Joomla installations should assess and mitigate this vulnerability to prevent unauthorized custom field creation. This includes reviewing the vulnerability's impact on their specific environments and taking steps to protect against potential exploitation.

Technical summary

The vulnerability is caused by an improper access check in webservices endpoints, allowing unauthorized users to create custom fields. The CVSS score is 6.4, indicating a medium severity. The vulnerability is classified under CWE-284. This improper access check could lead to unauthorized data modification.

Defensive priority

Medium priority due to the potential for unauthorized data modification.

Recommended defensive actions

  • Assess Joomla installations for exposure
  • Implement compensating controls to restrict webservices endpoint access
  • Monitor for suspicious custom field creation activity
  • Apply vendor remediation when available
  • Review compensating controls for exposed systems while remediation is scheduled and verified

Evidence notes

Evidence is limited; primary official records indicate an improper access check allows unauthorized custom field creation. Further verification is needed to determine affected scope and inventory. Defenders should verify the existence of affected Joomla installations and review official advisories for guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-48958 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-48958

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-48958 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-48958

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://developer.joomla.org/security-centre/1066-20260712-core-incorrect-access-control-in-com-fields-webservice-endpoints.html

    [email protected]

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.