---
id: pr-vllm-28846
repo: vllm-project/vllm
pr: 28846
title: '[Bugfix] Safeguard against missing backend in AttentionBackendEnum'
author: jesse996
date: '2025-11-18'
url: https://github.com/vllm-project/vllm/pull/28846
source_category: upstream-code
architectures:
- sm100
tags: []
techniques: []
hardware_features: []
kernel_types: []
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: 285eaa42857ba2a8f377fdd0dcd84120260d8f65
inclusion_reason: defer
changed_paths:
- vllm/attention/layer.py
artifact_dir: evidence/pull-bundles/vllm/gh-28846
head_ref_oid: 626c30f734fb8e4edefa252332a1e6eb0e972964
---
# [Bugfix] Safeguard against missing backend in AttentionBackendEnum

- Repository: `vllm-project/vllm`
- PR: [28846](https://github.com/vllm-project/vllm/pull/28846)
- Decision: `defer`
- Reason: defer

## Changed Paths

- `vllm/attention/layer.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-28846`
