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CVE Record

CVE-2026-48939: Joomla Extension - icagenda.com - Remote Code Execution in iCaganda extension for Joomla < 4.0.8/3.9.15

A vulnerability in the iCagenda extension for Joomla allows the upload of arbitrary files in the file attachment feature, ultimately resulting in PHP code upload and execution.

CriticalCVSS 10Known exploitedUpdated
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Glexia's TakeHuman reviewedcritical

Security readout for executives and security teams

Plain-English summary

CVE-2026-48939 is a critical flaw in the iCagenda Joomla extension. Unauthenticated attackers can upload arbitrary files through the attachment feature, leading to PHP code execution. CISA KEV listing indicates known exploitation. Joomla sites using affected iCagenda versions should be treated as urgent remediation targets.

Executive priority

Treat as emergency priority for any public Joomla site using iCagenda. The vulnerability is critical, remotely exploitable, and listed by CISA as known exploited. Business impact can include full site compromise, malware hosting, data theft, or pivoting into connected systems.

Technical view

The issue is CWE-434 unrestricted file upload in iCagenda for Joomla versions 3.2.1 through 4.0.7. The CVE describes arbitrary file upload via attachments, resulting in PHP execution. CVSS 4.0 score is 10.0. Vendor changelogs identify fixed releases 3.9.15 and 4.0.8.

Likely exposure

Internet-facing Joomla sites with the iCagenda extension installed, especially where the file attachment feature is enabled, are the primary exposure. Sites on versions before 3.9.15 or 4.0.8 should be considered vulnerable based on the provided affected-version range.

Exploitation context

Active exploitation is supported by the CISA Known Exploited Vulnerabilities entry. The source bundle also includes a public GitHub reference tagged as exploit and a third-party advisory describing a zero-day file upload RCE. No further exploit details are needed for validation.

Researcher notes

Evidence is strong for affected versions, vulnerability class, and fixed releases. The CVE states PHP code upload and execution through attachments. Avoid relying only on version banners; confirm installed extension packages and inspect upload paths. The provided sources do not name a non-upgrade workaround.

Mitigation direction

  • Upgrade iCagenda to 3.9.15, 4.0.8, or later vendor-supported releases.
  • If immediate upgrade is not possible, check vendor guidance for temporary risk reduction.
  • Review and restrict attachment upload functionality until remediation is complete.
  • Prioritize externally reachable Joomla sites and high-value business systems first.

Validation and detection

  • Inventory Joomla sites for the iCagenda extension and installed version.
  • Confirm whether versions are 3.9.15, 4.0.8, or later.
  • Review web-accessible upload directories for unexpected PHP files.
  • Check web server and Joomla logs for suspicious attachment upload activity.
  • Validate remediation by confirming the patched extension version in administration interfaces.
Prepared
Reviewed
Confidence
high
Sources
8

Public sources used

Michael Williams reviewed this cited source version on .

Potential ATT&CK relevance

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 · medium confidence lookup

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 lookup
description · low confidence lookup

Execution 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 lookup
cve · low confidence lookup

CVE-2026-48939 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
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

Official CVE source material

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.

1CVSS vectors
5Timeline events
1ADP providers
7Source links

CISA KEV status

Status
Known exploited
Source
CISA-ADP
Date added
KEV reference

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: activeAutomatable: yesTechnical Impact: total

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
10CVSS 4.0CriticalCVSS: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——Joomla

Vulnerability scoring details

Base CVSS 4.0 score

10Critical
CVSS 4.0 vector shape for CVE-2026-48939Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. Added to KEVCISA-ADP

    CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.

  4. ADP timelineCISA-ADP

    CVE-2026-48939 added to CISA KEV

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvcother:kev
  • 2026-07-10T00:00:00.000Z: CVE-2026-48939 added to CISA KEV

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
icagenda.comiCagenda extension for Joomla3.2.1-4.0.7unaffected
Weakness

CWE details

CWE-434

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-434 · source CWE mapping

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.

Open CWE intelligenceSame-CWE CVEs