Moov signedxml: Unauthenticated denial of service in exclusive XML canonicalization

{
  "id": "f94216b7b211314961f5448a20cf7bba322a8839abb732c07a8891a6c557f4e5",
  "url": "https://osv.dev/vulnerability/GHSA-5588-rp99-5fjh",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Moov signedxml: Unauthenticated denial of service in exclusive XML canonicalization",
    "summary": "Exclusive XML canonicalization (`http://www.w3.org/2001/10/xml-exc-c14n#`) in `github.com/moov-io/signedxml` copied the entire accumulated namespace map at every node during `ValidateReferences()`, before any reference digest or signature check. For a chain of nested elements that each declare many unused namespace prefixes, that produced **O(m × depth²)** time and peak memory (`m` = prefixes per level). `beevik/etree` caps tree depth (~1024), but `m` is unbounded, so a small attacker-controlled document (on the order of 1 MB) could drive multi-gigabyte allocations and OOM the process. No valid signature, matching certificate, or authentication is required. This is the library’s core path for SAML / WS-Federation service providers, which canonicalize attacker-supplied XML prior to authentication. ### Affected - Package: `github.com/moov-io/signedxml` - Function: `ExclusiveCanonicalization` (`exclusivecanonicalization.go`) - Verified: **v1.4.0** and current default branch (commit `d79064a`). Earlier v1.2.x–v1.3.x releases are likely affected. ### Remediation Do not copy the whole namespace map per node. Maintain a single scope and push/pop only the prefixes introduced at each element. Replace linear prefix-in-scope scans with set lookups. Impose a defensive cap on in-scope namespace declarations and return an error rather than allocating unbounded memory. From @shuji-oh ``` Thanks for the fix — I re-ran my PoC against this branch and confirmed the memory blowup is gone. Before",
    "evidence": "osv:GHSA-5588-rp99-5fjh",
    "products": [
      {
        "name": {
          "value": "github.com/moov-io/signedxml",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.4.1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-5588-rp99-5fjh",
      "aliases": [
        "CVE-2026-113729",
        "GHSA-5588-rp99-5fjh"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.4.1"
                }
              ]
            }
          ],
          "package": {
            "name": "github.com/moov-io/signedxml",
            "purl": "pkg:golang/github.com/moov-io/signedxml",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-5588-rp99-5fjh/GHSA-5588-rp99-5fjh.json",
            "last_known_affected_version_range": "<= 1.4.0"
          }
        }
      ],
      "modified": "2026-10-21T16:45:04.150818554Z",
      "provider": "osv",
      "references": [
        "https://github.com/moov-io/signedxml/security/advisories/GHSA-5588-rp99-5fjh",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-113729",
        "https://github.com/moov-io/signedxml/commit/da2cd6126c4c53b7e59a367d287786e6f6a2d0d3",
        "https://github.com/moov-io/signedxml",
        "https://github.com/moov-io/signedxml/releases/tag/v1.4.1"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-400",
          "CWE-407",
          "CWE-770"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": "2026-10-20T22:19:29Z",
        "github_reviewed_at": "2026-10-21T16:27:55Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-113729",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 394539,
  "published_at": "2026-10-21T16:27:55+00:00"
}