rust-russh — security advisory

{
  "id": "5eda065d5a6f572b2e7560e68d6d01ebb82d3ba2b6acb833791632e527ca3fcb",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-102820",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-102820",
    "summary": "pageant provides a [PageantStream] type that implements [AsyncRead] and [AsyncWrite] traits and can be used to talk to a running Pageant instance. Prior to pageant 0.2.3, the Windows pageant crate's pageant/src/wmmessage.rs MemoryMap::read function trusts a peer-controlled u32 response length supplied through the 8192-byte Pageant shared-memory mapping reached by AgentClient::connect_pageant. A local process that impersonates the Pageant window can make query_pageant_direct allocate up to approximately 4 GiB and copy beyond the mapped view, reliably crashing a russh client and conditionally exposing adjacent committed memory. This issue is fixed in pageant 0.2.3.",
    "evidence": "osv:UBUNTU-CVE-2026-102820",
    "products": [
      {
        "name": {
          "value": "rust-russh",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "0.57.1-2",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-102820",
      "aliases": [
        "UBUNTU-CVE-2026-102820"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "rust-russh",
            "purl": "pkg:deb/ubuntu/rust-russh?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "0.57.1-2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-102820.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "librust-russh-dev",
                "binary_version": "0.57.1-2"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:57:56.055802022Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-102820"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-102820",
        "https://www.cve.org/CVERecord?id=CVE-2026-102820",
        "https://github.com/Eugeny/russh/security/advisories/GHSA-g4mp-vgx3-xrvm",
        "https://github.com/Eugeny/russh/commit/5d566989ebabfdebfe6b33243d31765a0812260b",
        "https://github.com/Eugeny/russh/releases/tag/v0.63.2"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-102820",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 357739,
  "published_at": "2026-09-29T19:17:00+00:00"
}