BREAKING
Vertex AI SDK Flaw Enabled Model Swap
How the Bucket Squatting Worked
1No staging_bucket set
2Predictable bucket name
3Attacker pre-creates it
4Artifact lands in attacker bucket
0s
Attack window
0s
PoC swap time
Malicious Model, Remote Code Execution
Reported, Then Fixed by Google
Partial fixv1.144.0
March 31, 2026
UUID added to bucket name
Complete fixv1.148.0
April 15, 2026
Ownership verification added
Set staging_bucket, Don't Trust Defaults
AI NEWS BLITZ
Unit 42 found a Vertex AI SDK flaw that let attackers swap models in seconds.