CVE-2026-62239

FlashAttention Symlink Attack via tarfile.extractall in hopper/setup.py

Published Jul 13, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Dao-ailab
Dao-ailab flash-attention
Vendors & Products Dao-ailab
Dao-ailab flash-attention
Type Values Removed Values Added
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.
Title FlashAttention Symlink Attack via tarfile.extractall in hopper/setup.py
Weaknesses CWE-59
References
Metrics cvssV3_1

{'score': 6.6, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 17, 2026, 5:54 PM
Reserved
Jul 13, 2026, 4:41 PM
Status
Deferred
Published
Jul 13, 2026, 10:16 PM
Modified
Oct 24, 2026, 10:10 PM