CVE-2026-62239

Published: Jul 13, 2026Modified: Jul 15, 2026Deferred

5.3

Vector

CVSS: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: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:XShow less

Source: disclosure@vulncheck.com (Secondary)

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.

Related CWEs

CWE-59

Improper Link Resolution Before File Access ('Link Following')

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

References (5)

https://github.com/Dao-AILab/flash-attention/commit/0816ef12f424c6ec94b057a72c275b14f6e6edb2

Source: disclosure@vulncheck.com

https://github.com/Dao-AILab/flash-attention/issues/2637

Source: disclosure@vulncheck.com

https://github.com/Dao-AILab/flash-attention/pull/2702

Source: disclosure@vulncheck.com

https://www.vulncheck.com/advisories/flashattention-symlink-attack-via-tarfile-extractall-in-hopper-setup-py

Source: disclosure@vulncheck.com

https://github.com/Dao-AILab/flash-attention/issues/2637

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

Timeline

No history available yet.