CVE-2026-62239
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.
Does this matter?
Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 4.0
- 5.3 MEDIUMCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.16% probability · 6th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-59
- Source
- disclosure@vulncheck.com
References
- https://github.com/Dao-AILab/flash-attention/commit/0816ef12f424c6ec94b057a72c275b14f6e6edb2
- https://github.com/Dao-AILab/flash-attention/issues/2637
- https://github.com/Dao-AILab/flash-attention/pull/2702
- https://www.vulncheck.com/advisories/flashattention-symlink-attack-via-tarfile-extractall-in-hopper-setup-py
- https://github.com/Dao-AILab/flash-attention/issues/2637
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.