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.
References
| Link | Resource |
|---|---|
| https://github.com/trailofbits/fickling/commit/41ce7cb01edd97072994039574a2301ebb3f463d | Patch |
| https://github.com/trailofbits/fickling/pull/278 | Issue Tracking Patch |
| https://github.com/trailofbits/fickling/releases/tag/v0.1.12 | Release Notes |
| https://github.com/trailofbits/fickling/security/advisories/GHSA-cffv-grgg-g429 | Exploit Third Party Advisory |
| https://github.com/trailofbits/fickling/security/advisories/GHSA-cffv-grgg-g429 | Exploit Third Party Advisory |
Configurations
History
10 Jul 2026, 15:00
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Trailofbits
Trailofbits fickling |
|
| CPE | cpe:2.3:a:trailofbits:fickling:*:*:*:*:*:python:*:* | |
| References | () https://github.com/trailofbits/fickling/commit/41ce7cb01edd97072994039574a2301ebb3f463d - Patch | |
| References | () https://github.com/trailofbits/fickling/pull/278 - Issue Tracking, Patch | |
| References | () https://github.com/trailofbits/fickling/releases/tag/v0.1.12 - Release Notes | |
| References | () https://github.com/trailofbits/fickling/security/advisories/GHSA-cffv-grgg-g429 - Exploit, Third Party Advisory |
06 Jul 2026, 16:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/trailofbits/fickling/security/advisories/GHSA-cffv-grgg-g429 - |
04 Jul 2026, 14:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-07-04 14:16
Updated : 2026-07-10 15:00
NVD link : CVE-2026-14535
Mitre link : CVE-2026-14535
CVE.ORG link : CVE-2026-14535
JSON object : View
Products Affected
trailofbits
- fickling
CWE
CWE-693
Protection Mechanism Failure
