{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "mcp-atlassian"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.22.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-10T18:01:22Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\nGHSA-7r34-79r5-rcc9\u0027s fix added `validate_url_for_ssrf`, which resolves the attacker-controlled `X-Atlassian-{Jira,Confluence}-Url` header host **once at middleware time** and trusts the result. But the outbound request is later built with the **raw hostname** and **re-resolves at connect time with no IP pinning**. An attacker-controlled rebinding DNS name returns a public IP on the guard\u0027s lookup (validation passes) and `169.254.169.254` / an internal IP on the request\u0027s lookup (the socket connects there) \u2192 unauthenticated SSRF to cloud metadata / internal services on the **patched** build.\n\n### Relationship to CVE-2026-27826 / GHSA-7r34-79r5-rcc9 (incomplete fix \u2014 please read first)\nThis is an **incomplete-fix sibling** of the published `GHSA-7r34-79r5-rcc9` (the `X-Atlassian-*-Url` header SSRF). That fix (PR #986/#1005) added a single middleware-time resolve + allowlist DNS-skip, but **does not pin the validated IP to the connection** \u2014 the fetcher re-resolves the raw hostname at connect time, so the documented SSRF mitigation is incomplete against DNS-rebinding. The other advisory `GHSA-xjgw-4wvw-rgm4` (file-write) is unrelated. Verified live (2026-06-27): neither advisory, nor any open PR/issue (`rebind`/`TOCTOU`/`getaddrinfo`/`pin` \u2192 0), covers connect-time re-resolution. Filing as an incomplete-fix of GHSA-7r34 (not a standalone fresh SSRF).\n\n### Affected\n`src/mcp_atlassian/utils/urls.py` + `servers/main.py` + `servers/dependencies.py`, HEAD `ba72540` (PyPI `mcp-atlassian`, patched \u22650.17.0). **CWE-918** (SSRF) via **CWE-367** (TOCTOU).\n\n### Vulnerable code\n`utils/urls.py` `validate_url_for_ssrf` (\u2248184-205) resolves + validates, then returns a **string verdict, not a pinned IP**:\n```python\ndef validate_url_for_ssrf(url: str) -\u003e str | None:   # returns an error string or None \u2014 NO IP is pinned\n    ...\n    # resolves the host, checks each resolved IP is global, then DISCARDS the IP\n```\n`servers/main.py:526,534` calls it once in middleware. `servers/dependencies.py:544-561` then builds the fetcher with `url = \u003craw header hostname\u003e` (no pinned IP, no custom resolver / cached-getaddrinfo adapter), so the actual request re-resolves the name.\n\n### PoC (executed \u2014 boundary demonstration)\nThe PoC loads the **real** `urls.py` by path (`importlib`, `sha256` printed) and drives the genuine `validate_url_for_ssrf`, simulating the two resolutions via `getaddrinfo`:\n```\n[CHECK ] validate_url_for_ssrf(\u0027http://rebind.attacker.example\u0027) -\u003e None        (getaddrinfo#1 = 93.184.216.34 global -\u003e guard PASSED)\n[CONNECT] getaddrinfo call #2 returned 169.254.169.254 -\u003e the socket connects HERE\n[PROOF ] guard validated IP 93.184.216.34 but connection targets 169.254.169.254  =\u003e SSRF on the PATCHED build\n[CONTROL] if guard SAW 169.254.169.254 at check time -\u003e blocks it correctly\n[PIN   ] validate_url_for_ssrf returns a verdict (None), NOT an IP; dependencies.py builds url=raw hostname -\u003e NO pin\nALL PoC ASSERTIONS PASSED \u2014 DNS-rebind TOCTOU bypass demonstrated.\n```\n**Honest scope of the PoC:** this is a **boundary** demonstration \u2014 it proves the structural TOCTOU (the guard validates an IP it then discards; the connection re-resolves an unpinned hostname). It does **not** demonstrate a live end-to-end SSRF on a running server; that additionally requires an attacker-controlled fast-rebinding authoritative DNS responder winning the resolve\u2192connect window. Flagging this explicitly rather than overclaiming.\n\n### Impact\nSame as parent GHSA-7r34 (unauth read of cloud-metadata IAM creds / internal-service reach), reachable again on the patched version. The `X-Atlassian-*-Url` headers are processed in `UserTokenMiddleware` before fetcher creation, so an unauthenticated/low-priv caller controls the host.\n\n### Severity\n**High \u2014 CVSS v3.1 `AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N` \u2248 7.x**, aligned to the parent (8.2) with `AC:H` for the rebinding-race precondition. Honest caveat (above): the executed PoC proves the missing IP-pin structurally; a live exploit additionally needs an attacker rebinding-DNS. Not Critical.\n\n### Remediation\nPin the connection to the IP that `validate_url_for_ssrf` validated: use a custom resolver / cached-`getaddrinfo` `requests`-adapter (or pass the validated IP with a `Host` header), so the connect cannot re-resolve to a different address.\n\n### Dedup / freshness (re-verified live 2026-06-27)\nAdvisories `GHSA-7r34-79r5-rcc9` (original header SSRF this bypasses) + `GHSA-xjgw-4wvw-rgm4` (file-write, unrelated). Neither covers connect-time re-resolution / rebinding. PR [#986](https://github.com/sooperset/mcp-atlassian/pull/986)/[#1005](https://github.com/sooperset/mcp-atlassian/pull/1005) (the fix) add a single middleware-time resolve + allowlist DNS-skip, no pinning. `gh search prs/issues` for rebind/TOCTOU/getaddrinfo/pin \u2192 0. First-party code. **Fresh** at HEAD `ba72540`.",
  "id": "GHSA-489g-7rxv-6c8q",
  "modified": "2026-07-10T18:01:22Z",
  "published": "2026-07-10T18:01:22Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-489g-7rxv-6c8q"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/sooperset/mcp-atlassian"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "MCP Atlassian: DNS-rebinding TOCTOU bypass of the SSRF fix (CVE-2026-27826)"
}