{"id":"PYSEC-2026-2150","details":"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 MLAllowlist's deduplication logic.","aliases":["CVE-2026-14535","GHSA-cffv-grgg-g429"],"modified":"2026-07-13T07:15:25.026515566Z","published":"2026-07-04T14:16:29.063Z","references":[{"type":"ADVISORY","url":"https://github.com/trailofbits/fickling/releases/tag/v0.1.12"},{"type":"FIX","url":"https://github.com/trailofbits/fickling/commit/41ce7cb01edd97072994039574a2301ebb3f463d"},{"type":"FIX","url":"https://github.com/trailofbits/fickling/pull/278"},{"type":"EVIDENCE","url":"https://github.com/trailofbits/fickling/security/advisories/GHSA-cffv-grgg-g429"}],"affected":[{"package":{"name":"fickling","ecosystem":"PyPI","purl":"pkg:pypi/fickling"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.12"}]}],"versions":["0.0.1","0.0.2","0.0.3","0.0.4","0.0.5","0.0.6","0.0.7","0.0.8","0.1.10","0.1.11","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/fickling/PYSEC-2026-2150.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}