Vulnerability-Lookup

CVE-2026-73845 (GCVE-0-2026-73845)

Vulnerability from cvelistv5 – Published: 2026-08-14 16:45 – Updated: 2026-08-14 18:06

Title

CKAN MCP Server: MQA server allowlist bypass via unanchored regex (`isValidMqaServer`)

Summary

CKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, the ckan_get_mqa_quality and ckan_get_mqa_quality_details tools in src/tools/quality.ts use isValidMqaServer to validate the server_url parameter with a prefix-only regular expression for dati.gov.it, allowing suffix-host and URL-userinfo values to target an attacker-controlled host and return a spoofed response. This issue is fixed in version 0.4.112.

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-14 17:41 UTC

CWE

CWE-20 - Improper Input Validation
CWE-625 - Permissive Regular Expression
CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M mitre root Scorecard

References

3 references

URL	Tags
https://github.com/ondata/ckan-mcp-server/securit…	x_refsource_CONFIRM
https://github.com/ondata/ckan-mcp-server/commit/…	x_refsource_MISC
https://github.com/ondata/ckan-mcp-server/release…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
ondata	ckan-mcp-server	Affected: < 0.4.112

Show details on NVD website

JSON

To clipboard

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EUVD-2026-352816

European Vulnerability Database identifier assigned by ENISA

Reserved

2026-10-02 08:21

Assigner

ENISA

Alias of

a CVE record, shown under related vulnerabilities. This identifier carries no description, severity or references of its own: they belong to that CVE.

JSON

To clipboard

{
  "assigner": "ENISA",
  "date_reserved": "2026-10-02T08:21:32.253663+00:00",
  "id": "EUVD-2026-352816"
}

FKIE_CVE-2026-73845

Vulnerability from fkie_nvd - Published: 2026-08-14 17:20 - Updated: 2026-09-18 20:09

Severity

5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/ondata/ckan-mcp-server/commit/8e1522f9bbfa1f3b21550f17887f60f133e24151
	security-advisories@github.com	https://github.com/ondata/ckan-mcp-server/releases/tag/v0.4.112
	security-advisories@github.com	https://github.com/ondata/ckan-mcp-server/security/advisories/GHSA-83x6-42hr-jc76

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "ckan-mcp-server",
          "vendor": "ondata",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.4.112"
            }
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      "lang": "en",
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    }
  ],
  "id": "CVE-2026-73845",
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          "confidentialityImpact": "LOW",
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        },
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          "lang": "en",
          "value": "CWE-918"
        }
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}

GHSA-83X6-42HR-JC76

Vulnerability from github – Published: 2026-09-02 14:52 – Updated: 2026-09-02 14:52

Summary

CKAN MCP Server: MQA server allowlist bypass via unanchored regex (`isValidMqaServer`)

Details

Summary

The ckan_get_mqa_quality and ckan_get_mqa_quality_details tools restrict their server_url argument to dati.gov.it via a regular expression. The regex is anchored only at the start and places no boundary after the host, so any URL whose host merely begins with dati.gov.it — or that uses dati.gov.it as URL userinfo before an @ — passes validation while actually targeting an attacker-controlled host.

Affected code

// src/tools/quality.ts
const ALLOWED_SERVER_PATTERNS = [
  /^https?:\/\/(www\.)?dati\.gov\.it/i        // <-- no end anchor / host boundary
];
export function isValidMqaServer(serverUrl: string): boolean {
  return ALLOWED_SERVER_PATTERNS.some(pattern => pattern.test(serverUrl));
}

All of the following return true:

URL	Real host
`https://dati.gov.it.attacker.com/x`	`dati.gov.it.attacker.com` (attacker)
`http://dati.gov.it.evil.example/api`	`dati.gov.it.evil.example` (attacker)
`https://dati.gov.it@attacker.com/x`	`attacker.com` (userinfo trick)

After passing this check, server_url flows into getMqaQuality/getMqaQualityDetails, which call makeCkanRequest(serverUrl, "package_show", { id }). The server therefore issues a request to the attacker-controlled host and returns its (parsed) response to the caller.

Impact

The intended "dati.gov.it only" trust boundary for the MQA tools is defeated; they can be driven against arbitrary external hosts.
The attacker host receives the request (including the dataset_id) and controls the response body that is surfaced back to the model/user — enabling response spoofing and, in an agentic setting, indirect prompt-injection content delivered under the guise of a trusted-portal tool.
Contributes to SSRF surface: while makeCkanRequest blocks private/internal IPs, this bypass removes the domain restriction that the code intends to enforce for these tools.

The @-userinfo variant is the most severe form because validation passes on a string whose actual host is fully attacker-chosen.

Proof of concept

poc/mqa-allowlist-poc.mjs runs the verbatim regex over benign and malicious URLs:

accepted  expected_legit  url
true      true            https://dati.gov.it/opendata          <- legit
true      false           https://dati.gov.it.attacker.com/x    <- BYPASS
true      false           http://dati.gov.it.evil.example/api   <- BYPASS
true      false           https://dati.gov.it@attacker.com/x    <- BYPASS

Remediation

Validate the parsed host, not the raw string. For example:

function isValidMqaServer(serverUrl) {
  let u; try { u = new URL(serverUrl); } catch { return false; }
  if (u.protocol !== "https:") return false;
  const h = u.hostname.toLowerCase();
  return h === "dati.gov.it" || h === "www.dati.gov.it";
  // or: h === "dati.gov.it" || h.endsWith(".dati.gov.it")
}

Anchoring the regex end-to-end (/^https:\/\/(www\.)?dati\.gov\.it(\/|$)/i) also closes the suffix trick, but URL-parsing + exact host comparison is the robust fix and also neutralizes the @-userinfo variant.

Severity

5.3 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@aborruso/ckan-mcp-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.4.112"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-73845"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20",
      "CWE-625",
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-02T14:52:21Z",
    "nvd_published_at": "2026-08-14T17:20:36Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nThe `ckan_get_mqa_quality` and `ckan_get_mqa_quality_details` tools restrict their `server_url` argument to `dati.gov.it` via a regular expression. The regex is anchored only at the start and places no boundary after the host, so any URL whose host merely **begins with** `dati.gov.it` \u2014 or that uses `dati.gov.it` as URL *userinfo* before an `@` \u2014 passes validation while actually targeting an attacker-controlled host.\n\n## Affected code\n\n```js\n// src/tools/quality.ts\nconst ALLOWED_SERVER_PATTERNS = [\n  /^https?:\\/\\/(www\\.)?dati\\.gov\\.it/i        // \u003c-- no end anchor / host boundary\n];\nexport function isValidMqaServer(serverUrl: string): boolean {\n  return ALLOWED_SERVER_PATTERNS.some(pattern =\u003e pattern.test(serverUrl));\n}\n```\n\nAll of the following return `true`:\n\n| URL | Real host |\n|-----|-----------|\n| `https://dati.gov.it.attacker.com/x` | `dati.gov.it.attacker.com` (attacker) |\n| `http://dati.gov.it.evil.example/api` | `dati.gov.it.evil.example` (attacker) |\n| `https://dati.gov.it@attacker.com/x` | `attacker.com` (userinfo trick) |\n\nAfter passing this check, `server_url` flows into `getMqaQuality`/`getMqaQualityDetails`, which call `makeCkanRequest(serverUrl, \"package_show\", { id })`. The server therefore issues a request to the attacker-controlled host and returns its (parsed) response to the caller.\n\n## Impact\n\n- The intended \"dati.gov.it only\" trust boundary for the MQA tools is defeated; they can be driven against arbitrary external hosts.\n- The attacker host receives the request (including the `dataset_id`) and controls the response body that is surfaced back to the model/user \u2014 enabling response spoofing and, in an agentic setting, indirect prompt-injection content delivered under the guise of a trusted-portal tool.\n- Contributes to SSRF surface: while `makeCkanRequest` blocks private/internal IPs, this bypass removes the domain restriction that the code intends to enforce for these tools.\n\nThe `@`-userinfo variant is the most severe form because validation passes on a string whose *actual* host is fully attacker-chosen.\n\n## Proof of concept\n\n`poc/mqa-allowlist-poc.mjs` runs the verbatim regex over benign and malicious URLs:\n\n```\naccepted  expected_legit  url\ntrue      true            https://dati.gov.it/opendata          \u003c- legit\ntrue      false           https://dati.gov.it.attacker.com/x    \u003c- BYPASS\ntrue      false           http://dati.gov.it.evil.example/api   \u003c- BYPASS\ntrue      false           https://dati.gov.it@attacker.com/x    \u003c- BYPASS\n```\n\n## Remediation\n\nValidate the parsed host, not the raw string. For example:\n\n```js\nfunction isValidMqaServer(serverUrl) {\n  let u; try { u = new URL(serverUrl); } catch { return false; }\n  if (u.protocol !== \"https:\") return false;\n  const h = u.hostname.toLowerCase();\n  return h === \"dati.gov.it\" || h === \"www.dati.gov.it\";\n  // or: h === \"dati.gov.it\" || h.endsWith(\".dati.gov.it\")\n}\n```\n\nAnchoring the regex end-to-end (`/^https:\\/\\/(www\\.)?dati\\.gov\\.it(\\/|$)/i`) also closes the suffix trick, but URL-parsing + exact host comparison is the robust fix and also neutralizes the `@`-userinfo variant.",
  "id": "GHSA-83x6-42hr-jc76",
  "modified": "2026-09-02T14:52:21Z",
  "published": "2026-09-02T14:52:21Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/ondata/ckan-mcp-server/security/advisories/GHSA-83x6-42hr-jc76"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73845"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ondata/ckan-mcp-server/commit/8e1522f9bbfa1f3b21550f17887f60f133e24151"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ondata/ckan-mcp-server"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ondata/ckan-mcp-server/releases/tag/v0.4.112"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "CKAN MCP Server: MQA server allowlist bypass via unanchored regex (`isValidMqaServer`)"
}

Sightings

Author	Source	Type	Date	Other

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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.
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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-2026-73845 (GCVE-0-2026-73845)

EUVD-2026-352816

FKIE_CVE-2026-73845

GHSA-83X6-42HR-JC76

Summary

Affected code

Impact

Proof of concept

Remediation

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