CVE-2026-44219: ciguard SCA HTTP Client Reads Response Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xw8c-rrvx-f7xq",
  "modified" : "2026-05-15T23:50:38Z",
  "published" : "2026-05-05T22:17:43Z",
  "aliases" : [ "CVE-2026-44219" ],
  "summary" : "ciguard: SCA HTTP client reads response body without size cap",
  "details" : "## Summary\n\nBoth SCA HTTP clients (`src/ciguard/analyzer/sca/osv.py` and `src/ciguard/analyzer/sca/endoflife.py`) call `payload = json.loads(resp.read().decode('utf-8'))` without a maximum-bytes cap. A hostile or compromised endoflife.date / OSV.dev (or a successful TLS MITM) could return a multi-GB response, exhausting the ciguard process's memory.\n\n## Threat scenario\n\nciguard process memory exhaustion → OOM kill or system swap thrash. Realistic when ciguard runs in CI with a limited memory budget (typical: 4-8 GB). No data integrity or confidentiality impact.\n\n**Realism caveat:** both URLs are hardcoded HTTPS, so this is a low-realism threat (HTTPS prevents MITM unless the attacker controls a trusted CA or hijacks DNS in a way that doesn't trigger cert validation). The unbounded read is structural defence-in-depth, not a directly exploitable bug today.\n\n## Patch\n\n- New `MAX_RESPONSE_BYTES = 5 * 1024 * 1024` (5 MB) constant in both modules.\n- `body = resp.read(MAX_RESPONSE_BYTES + 1)` with overflow check returns `None` (caller falls back to stale cache).\n- 3 regression tests in `tests/test_sca_rules.py::TestSCAResponseSizeCap`.\n\n## Discovery\n\nFound during ciguard's first self-conducted pentest cycle, 2026-04-26.\n\n## CVSS Scoring\n\n- CVSS v3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L` — 3.7 (Low)\n- CVSS v4.0: `CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N` — first.org calc 3.1 (Low); GitHub's calc 6.3 (Medium). Vector is correct — choosing v3.1 as the structured score keeps the consistent Low rating across consumers.\n\n## Reproduction\n\nMonkey-patch `urllib.request.urlopen` to return a fake 50 MB response; observe memory growth before/after the call. Pre-fix: process memory grows by ~50 MB. Post-fix: `_fetch` returns `None`, memory growth bounded to MAX_RESPONSE_BYTES.\n\n## References\n\n- Fix released in [v0.8.2](https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.2)\n- CI regression gate added in [v0.8.3](https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.3)\n- https://www.cve.org/CVERecord?id=CVE-2026-44219",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ciguard"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.6.0"
      }, {
        "fixed" : "0.8.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.8.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Jo-Jo98/ciguard/security/advisories/GHSA-xw8c-rrvx-f7xq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44219"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Jo-Jo98/ciguard"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-05T22:17:43Z",
    "nvd_published_at" : "2026-05-12T20:16:42Z"
  }
}