Vulnerability-Lookup

GHSA-537C-GP6X-JR7Q

Vulnerability from github – Published: 2026-08-25 18:31 – Updated: 2026-09-01 21:31

Details

The Kaltura HTML5 player (mwEmbed / html5lib) contains an unauthenticated remote code execution vulnerability caused by unsafe data deserialization and unsanitized filesystem path construction. mwEmbedLoader.php accepts a user‑controlled ServiceUrl, whose response is passed to unserialize(), and the resulting object’s fields are written to a cache path derived from attacker‑supplied uiconf_id without proper path validation. An attacker can write arbitrary files into web‑accessible locations and achieve code execution as the webserver user. Affected versions include html5lib v2.45, v2.103 and earlier, and other v2.x releases exposing the vulnerable endpoint.

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-19912"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-25T17:17:07Z",
    "severity": "CRITICAL"
  },
  "details": "The Kaltura HTML5 player (mwEmbed / html5lib) contains an unauthenticated remote code execution vulnerability caused by unsafe data deserialization and unsanitized filesystem path construction. mwEmbedLoader.php accepts a user\u2011controlled ServiceUrl, whose response is passed to unserialize(), and the resulting object\u2019s fields are written to a cache path derived from attacker\u2011supplied uiconf_id without proper path validation. An attacker can write arbitrary files into web\u2011accessible locations and achieve code execution as the webserver user. Affected versions include html5lib v2.45, v2.103 and earlier, and other v2.x releases exposing the vulnerable endpoint.",
  "id": "GHSA-537c-gp6x-jr7q",
  "modified": "2026-09-01T21:31:24Z",
  "published": "2026-08-25T18:31:55Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19912"
    },
    {
      "type": "WEB",
      "url": "https://kb.cert.org/vuls/id/308749"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-19912 (GCVE-0-2026-19912)

Vulnerability from cvelistv5 – Published: 2026-08-25 16:20 – Updated: 2026-09-01 18:23

Title

CVE-2026-19912

Summary

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-01 18:23 UTC

CWE

CWE-20 Improper Input Validation
CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-20 - Improper Input Validation
CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Assigner

certcc mitre root

References

1 reference

URL	Tags
https://kb.cert.org/vuls/id/308749

Impacted products

1 product

Vendor	Product	Version
Kaltura	Kaltura HTML5 Video Player, html5 library	Affected: 0 , ≤ v2.103 (custom) Affected: 2.45

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-19912",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-01T18:23:34.720113Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-20",
                "description": "CWE-20 Improper Input Validation",
                "lang": "en",
                "type": "CWE"
              },
              {
                "cweId": "CWE-22",
                "description": "CWE-22 Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-01T18:23:56.204Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Kaltura HTML5 Video Player, html5 library",
          "vendor": "Kaltura",
          "versions": [
            {
              "lessThanOrEqual": "v2.103",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            },
            {
              "status": "affected",
              "version": "2.45"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Kaltura HTML5 player (mwEmbed / html5lib) contains an unauthenticated remote code execution vulnerability caused by unsafe data deserialization and unsanitized filesystem path construction. mwEmbedLoader.php accepts a user\u2011controlled ServiceUrl, whose response is passed to unserialize(), and the resulting object\u2019s fields are written to a cache path derived from attacker\u2011supplied uiconf_id without proper path validation. An attacker can write arbitrary files into web\u2011accessible locations and achieve code execution as the webserver user. Affected versions include html5lib v2.45, v2.103 and earlier, and other v2.x releases exposing the vulnerable endpoint."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-20 Improper Input Validation",
              "lang": "en"
            }
          ]
        },
        {
          "descriptions": [
            {
              "description": "CWE-22 Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T16:32:58.890Z",
        "orgId": "37e5125f-f79b-445b-8fad-9564f167944b",
        "shortName": "certcc"
      },
      "references": [
        {
          "url": "https://kb.cert.org/vuls/id/308749"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "CVE-2026-19912",
      "x_generator": {
        "engine": "VINCE 3.0.45",
        "env": "prod",
        "origin": "https://cveawg.mitre.org/api/cve/CVE-2026-19912"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b",
    "assignerShortName": "certcc",
    "cveId": "CVE-2026-19912",
    "datePublished": "2026-08-25T16:20:45.532Z",
    "dateReserved": "2026-08-14T20:07:50.299Z",
    "dateUpdated": "2026-09-01T18:23:56.204Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.