Buffa: Use-After-Free in OwnedView via Unsound 'static Lifetime Promotion in Deref

{
  "id": "c004c3cf9c17bf2398b72a1792f6ccd4f8f0d5cca3dee4b800cf5b98acbb2dfa",
  "url": "https://osv.dev/vulnerability/CVE-2026-55406",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Buffa: Use-After-Free in OwnedView via Unsound 'static Lifetime Promotion in Deref",
    "summary": "Buffa is a pure-Rust Protocol Buffers implementation with first-class protobuf editions support. Prior to 0.7.0, a soundness bug in the OwnedView type allowed safe Rust code to trigger a use-after-free: the OwnedView::decode constructor transmuted a borrowed slice to &'static [u8], and the Deref implementation exposed the promoted 'static lifetime on borrowed view fields (such as &'static str and &'static [u8]) to callers, so the borrow checker permitted those references to outlive the OwnedView; once the OwnedView was dropped and its backing buffer freed, the references became dangling, enabling memory corruption, information disclosure of freed heap contents, and cross-thread misuse without any unsafe code in the calling application. This issue is fixed in version 0.7.0.",
    "evidence": "osv:CVE-2026-55406",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-55406",
      "aliases": [
        "CVE-2026-55406",
        "GHSA-9pwq-gcrx-wghh"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/anthropics/buffa",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "9ce9ab74e4ea18c3abda901b4054fea3fa193349"
                },
                {
                  "fixed": "7dcf50a1a40eca6ed8d6c6dd59f4310aa0d68b0e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.7.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "7dcf50a1a40eca6ed8d6c6dd59f4310aa0d68b0e"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "9ce9ab74e4ea18c3abda901b4054fea3fa193349"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v0.7.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.3.0",
            "v0.1.0",
            "v0.2.0",
            "v0.6.0",
            "v0.5.0",
            "v0.4.0",
            "v0.5.2",
            "v0.5.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55406.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.951497579Z",
      "provider": "osv",
      "references": [
        "https://github.com/anthropics/buffa/releases/tag/v0.7.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55406.json",
        "https://github.com/anthropics/buffa/security/advisories/GHSA-9pwq-gcrx-wghh",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-55406",
        "https://github.com/anthropics/buffa/commit/7dcf50a1a40eca6ed8d6c6dd59f4310aa0d68b0e",
        "https://github.com/anthropics/buffa/pull/154"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-200",
          "CWE-416"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55406.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-55406",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 496871,
  "published_at": "2026-07-16T15:54:29.511+00:00"
}