Vulnerability-Lookup

CVE-2026-77991 (GCVE-0-2026-77991)

Vulnerability from cvelistv5 – Published: 2026-08-27 05:50 – Updated: 2026-08-28 07:47

Title

Joomla Extension - joomlaeventmanager.net - Privileged remote code execution in Joomla Event Manager < 5.0.1

Summary

Joomla Extension - joomlaeventmanager.net - Privileged remote code execution in Joomla Event Manager < 5.0.1 - The administrator source model allows to write dangerous file type incl. PHP, leading to remote code execution.

Severity

9.4 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-27 13:45 UTC

CWE

CWE-434 - Unrestricted Upload of File with Dangerous Type

Assigner

Joomla mitre root

References

1 reference

URL	Tags
https://www.joomlaeventmanager.net/	product

Impacted products

1 product

Vendor	Product	Version	CPE status
joomlaeventmanager.net	JEM - Joomla Event Manager extension for Joomla	Affected: 1.0.0-5.0.0	guessed

Credits

Phil Taylor, mysites.guru

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-77991

Vulnerability from fkie_nvd - Published: 2026-08-27 06:17 - Updated: 2026-08-28 16:09

Severity

9.4 (Critical) - CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Summary

References

	URL	Tags
	security@joomla.org	https://www.joomlaeventmanager.net/

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "JEM - Joomla Event Manager extension for Joomla",
          "vendor": "joomlaeventmanager.net",
          "versions": [
            {
              "status": "affected",
              "version": "1.0.0-5.0.0"
            }
          ]
        }
      ],
      "source": "security@joomla.org"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Joomla Extension - joomlaeventmanager.net - Privileged remote code execution in Joomla Event Manager \u003c 5.0.1 - The administrator source model allows to write dangerous file type incl. PHP, leading to remote code execution."
    }
  ],
  "id": "CVE-2026-77991",
  "lastModified": "2026-08-28T16:09:10.947",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
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          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.4,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
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          "providerUrgency": "NOT_DEFINED",
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          "subIntegrityImpact": "HIGH",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
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          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
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GHSA-GH3C-9WWF-MJ2V

Vulnerability from github – Published: 2026-08-27 06:31 – Updated: 2026-08-27 06:31

Details

Severity

9.4 (Critical)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-77991"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-434"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-27T06:17:28Z",
    "severity": "CRITICAL"
  },
  "details": "Joomla Extension - joomlaeventmanager.net - Privileged remote code execution in Joomla Event Manager \u003c 5.0.1 - The administrator source model allows to write dangerous file type incl. PHP, leading to remote code execution.",
  "id": "GHSA-gh3c-9wwf-mj2v",
  "modified": "2026-08-27T06:31:36Z",
  "published": "2026-08-27T06:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77991"
    },
    {
      "type": "WEB",
      "url": "https://www.joomlaeventmanager.net"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-77991 (GCVE-0-2026-77991)

FKIE_CVE-2026-77991

GHSA-GH3C-9WWF-MJ2V

Tags

Sightings

Nomenclature

Related by attack behaviour