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GHSA-4XWW-RQHR-67W2

Vulnerability from github – Published: 2026-08-27 15:31 – Updated: 2026-08-27 15:31

Details

The patch adds explicit Mermaid detection and HTML escaping around the token content before the generated Mermaid wrapper is returned. It also moves the wrapping logic earlier in page initialization so Markdown instances are protected consistently.

Version impacted >= 3.3.0

Severity

5.1 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-81753"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-27T13:18:43Z",
    "severity": "MODERATE"
  },
  "details": "Affected versions of Flowintel render Mermaid blocks contained in stored case notes without sufficiently neutralizing attacker-controlled markup. Because Mermaid note content is persisted and later rendered for other users, an attacker with permission to create or edit a note could store a crafted Mermaid payload that results in JavaScript execution when another user views the affected case note.\n\nThe patch adds explicit Mermaid detection and HTML escaping around the token content before the generated Mermaid wrapper is returned. It also moves the wrapping logic earlier in page initialization so Markdown instances are protected consistently.\n\nVersion impacted \u003e= 3.3.0",
  "id": "GHSA-4xww-rqhr-67w2",
  "modified": "2026-08-27T15:31:37Z",
  "published": "2026-08-27T15:31:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81753"
    },
    {
      "type": "WEB",
      "url": "https://github.com/flowintel/flowintel/commit/61c97e67f5d04030f26e7900c470b52f9f37da06"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/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"
    }
  ]
}

CVE-2026-81753 (GCVE-0-2026-81753)

Vulnerability from cvelistv5 – Published: 2026-08-27 12:06 – Updated: 2026-08-27 15:54

Title

Flowintel Stored XSS in Case Notes via Malicious Mermaid Diagram Content

Summary

Affected versions of Flowintel render Mermaid blocks contained in stored case notes without sufficiently neutralizing attacker-controlled markup. Because Mermaid note content is persisted and later rendered for other users, an attacker with permission to create or edit a note could store a crafted Mermaid payload that results in JavaScript execution when another user views the affected case note. The patch adds explicit Mermaid detection and HTML escaping around the token content before the generated Mermaid wrapper is returned. It also moves the wrapping logic earlier in page initialization so Markdown instances are protected consistently. Version impacted >= 3.3.0

Severity

5.1 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-27 15:54 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')

Assigner

CIRCL ENISA root

References

1 reference

URL	Tags
https://github.com/flowintel/flowintel/commit/61c…	patch

Impacted products

1 product

Vendor	Product	Version
flowintel	flowintel	Affected: 0 , ≤ 3.3.0 (semver)

Credits

Jeroen Pinoy David Cruciani

Show details on NVD website

JSON

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        "metrics": [
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            "other": {
              "content": {
                "id": "CVE-2026-81753",
                "options": [
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                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-27T15:54:25.309820Z",
                "version": "2.0.3"
              },
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          "type": "finder",
          "value": "Jeroen Pinoy"
        },
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          "type": "remediation developer",
          "value": "David Cruciani"
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          "url": "https://github.com/flowintel/flowintel/commit/61c97e67f5d04030f26e7900c470b52f9f37da06"
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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.

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.

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GHSA-4XWW-RQHR-67W2

CVE-2026-81753 (GCVE-0-2026-81753)

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