CVE-2026-62239: Dao-Ailab Flash-Attention

Medium severity, CVSS 6.6. EPSS: 0.2% chance of exploitation in the next 30 days.

FlashAttention through 2.8.3.post1, fixed in commit 0816ef1, contains a symlink attack vulnerability in the download_and_copy() function within hopper/setup.py that extracts NVIDIA toolchain archives without validating symlinks or filtering tar members. A local attacker can pre-plant a symlink in the predictable cache directory to redirect extracted binaries to an attacker-chosen location, enabling arbitrary file write with victim privileges during build time.

Affected products

• Dao-Ailab Flash-Attention: up to and including 2.8.3.post1

Published 2026-07-13. Last modified 2026-09-17.