BadMerging: Backdoor Attacks Against Model Merging

Evidence card

Claim

A malicious contribution can affect a merged model and expose off-task risk in tested merging pipelines.

Evidence level

Experimentally observed

Source

https://arxiv.org/abs/2408.07362

Publication date

2024-08-14

Authors or institution

Jinghuai Zhang, Jianfeng Chi, Zheng Li, Kunlin Cai, Yang Zhang, Yuan Tian

System tested

Backdoored task-specific model contributions in model merging settings.

Limitations

Laboratory attack designs; defenses and transferability depend on merge algorithms and governance.

What the evidence does show

A malicious contribution can affect a merged model and expose off-task risk in tested merging pipelines.

What the evidence does not show

That every model merge is compromised or that attacks are undetectable under all audits.

Date last reviewed in UTC

2026-06-26T00:00:00Z