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. 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 v4.0

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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1

6.6 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

EPSS

0.16% chance of exploitation in the next 30 days, 6th percentile

Published

2026-07-13

Updated

2026-07-14

Proof-of-concept exploits (1)

• Dao-AILab/flash-attention/issues/2637

References

• CVE Record
• NVD entry

Related

• CVE-2026-6220
• CVE-2026-6224
• CVE-2026-6219
• CVE-2026-62240
• CVE-2026-62183
• CVE-2026-62242