{"data":{"id":"ada35663-8781-4420-8393-8a2b6c31c823","title":"Poison-then-Hide: Finetuning-Activated Backdoor Attack on Pretrained Vision Encoders","summary":"Poison-then-Hide is a finetuning-activated backdoor attack on pretrained vision encoders. The attack implants a dormant backdoor in the pretrained encoder and activates it when the full model is finetuned on clean downstream data in a domain transfer. The authors report up to 97% attack success rates across six datasets and three model architectures, and find that standard detection and mitigation defenses cannot fully remove the backdoor, which can reappear after benign finetuning.","solution":"N/A -- no mitigation discussed in source.","labels":["security","research"],"sourceUrl":"https://arxiv.org/abs/2611.14970v1","publishedAt":"2026-11-11T03:30:37.000Z","cveId":null,"cweIds":null,"cvssScore":null,"cvssSeverity":null,"severity":"info","attackType":["model_poisoning"],"issueType":"research","affectedPackages":null,"affectedPackageNames":null,"affectedPackageRefs":null,"affectedVendors":[],"affectedVendorsRaw":[],"classifierModel":"claude-haiku-5-5","classifierPromptVersion":"v4","summaryPromptVersion":"v2","headline":null,"headlinePromptVersion":null,"cvssVector":null,"attackVector":null,"attackComplexity":null,"privilegesRequired":null,"userInteraction":null,"exploitMaturity":null,"epssScore":null,"epssCheckedAt":null,"kevDateAdded":null,"advisoryAliases":null,"affectedPackagesSource":null,"affectedPackagesCheckedAt":null,"patchAvailable":null,"disclosureDate":"2026-11-11T03:30:37.000Z","fixReleasedAt":null,"daysToFix":null,"fixCheckedAt":null,"capecIds":null,"crossRefCount":0,"attackSophistication":"advanced","impactType":["integrity","safety"],"aiComponentTargeted":"model","llmSpecific":false,"classifierConfidence":0.95,"researchCategory":"preprint","atlasIds":null}}