Fickling MLAllowlist analysis pass rendered inoperative by shared mutable state in AnalysisContext.shorten_code()

{
  "id": "130132a364ef3f0e47f20d49c8e8882628a5678b942ead7b8924f8edcda3ec6f",
  "url": "https://osv.dev/vulnerability/CVE-2026-14535",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Fickling MLAllowlist analysis pass rendered inoperative by shared mutable state in AnalysisContext.shorten_code()",
    "summary": "In Trail of Bits fickling versions up to and including 0.1.11, the UnsafeImportsML analysis pass unconditionally calls AnalysisContext.shorten_code(node) on every import node it inspects, regardless of whether the import is flagged as unsafe. This call registers the shortened code representation in the shared AnalysisContext.reported_shortened_code set. When the MLAllowlist analysis pass subsequently runs, it calls the same shorten_code() method, receives already_reported=True for every import, and executes a continue statement that skips its allowlist check entirely. This renders MLAllowlist dead code for all imports — it never evaluates whether an import is in the ML allowlist or not. The MLAllowlist pass was designed to catch imports of modules outside the known-safe ML ecosystem (torch, numpy, transformers, etc.) that slip past the UnsafeImports denylist. With MLAllowlist inoperative, any standard library module not in the UNSAFE_IMPORTS denylist can be invoked via pickle deserialization while fickling's check_safety() returns LIKELY_SAFE. The fickling.load() API chains check_safety() into pickle.loads() as an explicit security gate, meaning a LIKELY_SAFE verdict causes the payload to be deserialized and executed. The root cause is shared mutable state between independently-correct analysis passes — UnsafeImportsML works as designed in isolation, MLAllowlist works as designed in isolation, but the shared reported_shortened_code set causes UnsafeImportsML to poison MLAllow",
    "evidence": "osv:CVE-2026-14535",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-14535",
      "aliases": [
        "CVE-2026-14535",
        "GHSA-cffv-grgg-g429",
        "PYSEC-2026-2150"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/trailofbits/fickling",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "41ce7cb01edd97072994039574a2301ebb3f463d"
                },
                {
                  "fixed": "c3c695cdcce451c04dfe892802675161614287a2"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:trailofbits:fickling:*:*:*:*:*:python:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.1.11"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "41ce7cb01edd97072994039574a2301ebb3f463d"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c3c695cdcce451c04dfe892802675161614287a2"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v0.1.12"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.1.11",
            "v0.1.10",
            "v0.1.9",
            "v0.1.8",
            "v0.1.7",
            "v0.1.6",
            "v0.1.5",
            "v0.1.4",
            "master",
            "v0.1.3",
            "v0.1.2",
            "v0.1.1",
            "v0.1.0",
            "v0.0.8",
            "v0.0.7",
            "v0.0.6",
            "v0.0.5",
            "v0.0.4",
            "v0.0.3",
            "v0.0.2",
            "v0.0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-14535.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.013737628Z",
      "provider": "osv",
      "references": [
        "https://github.com/trailofbits/fickling/releases/tag/v0.1.12",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/14xxx/CVE-2026-14535.json",
        "https://github.com/trailofbits/fickling/security/advisories/GHSA-cffv-grgg-g429",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-14535",
        "https://github.com/trailofbits/fickling/commit/41ce7cb01edd97072994039574a2301ebb3f463d",
        "https://github.com/trailofbits/fickling/pull/278",
        "https://pypi.org/project/fickling/"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-693"
        ],
        "cna_assigner": "BombadilSystems",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/14xxx/CVE-2026-14535.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-14535",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 509712,
  "published_at": "2026-07-04T13:31:14.937+00:00"
}