pageant: unbounded frame buffering on peer-controlled 4-byte length prefix (memory-exhaustion DoS)

{
  "id": "4f90abc6cc3de56193060a6c8e2326c8e081db451ac5dce491b43ec04a44c563",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-116775",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "pageant: unbounded frame buffering on peer-controlled 4-byte length prefix (memory-exhaustion DoS)",
    "summary": "pageant provides a PageantStream type that implements AsyncRead and AsyncWrite traits and can be used to communicate with a running Pageant instance. From 0.2.0 until 0.2.5, PageantStream::new in pageant/src/wmmessage.rs trusts a peer-controlled four-byte length prefix and buffers until len + 4 bytes are available without checking the fixed _AGENT_MAX_MSGLEN transport capacity. An application that bridges an SSH forwarded-agent channel to the raw stream can allow a malicious server to force large allocations or retain a partially filled frame, causing client memory exhaustion. This issue is fixed in version 0.2.5.",
    "evidence": "cve:CVE-2026-116775",
    "products": [
      {
        "name": {
          "value": "russh",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-116775",
      "aliases": [
        "CVE-2026-116775"
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "version": "4.0",
            "baseScore": 2.3,
            "attackVector": "NETWORK",
            "baseSeverity": "LOW",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
            "userInteraction": "PASSIVE",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "LOW",
            "subConfidentialityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE"
          }
        }
      ],
      "affected": [
        {
          "vendor": "Eugeny",
          "product": "russh",
          "versions": [
            {
              "status": "affected",
              "version": ">= 0.2.0, < 0.2.5"
            }
          ]
        }
      ],
      "modified": "2026-10-27T20:27:30.852Z",
      "provider": "cve",
      "references": [
        "https://github.com/Eugeny/russh/security/advisories/GHSA-662x-8wvj-2276",
        "https://github.com/Eugeny/russh/commit/69e4b55513eaa8ac9d2ad4236f13171fc164e10a",
        "https://github.com/Eugeny/russh/releases/tag/v0.65.0"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
          "shortName": "GitHub_M",
          "dateUpdated": "2026-10-27T20:27:30.852Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-116775",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 398628,
  "published_at": "2026-10-27T20:27:30.852+00:00"
}