CVE-2026-62239
FlashAttention Symlink Attack via tarfile.extractall in hopper/setup.py
CVSS Score
6.6
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-59 |
| Vendor | dao-ailab |
| Product | flash-attention |
| Published | Jul 13, 2026 |
| Last Updated | Jul 14, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
Dao-AILab / flash-attention
0 ≤ 2.8.3.post1
References
github.com: https://github.com/Dao-AILab/flash-attention/issues/2637 github.com: https://github.com/Dao-AILab/flash-attention/pull/2702 github.com: https://github.com/Dao-AILab/flash-attention/commit/0816ef12f424c6ec94b057a72c275b14f6e6edb2 vulncheck.com: https://www.vulncheck.com/advisories/flashattention-symlink-attack-via-tarfile-extractall-in-hopper-setup-py
Credits
YU SUN