Dao-AILab FlashAttention up to 2.8.3.post1 Archive Extraction hopper/setup.py download_and_copy symlink

Summaryinfo

A vulnerability has been found in Dao-AILab FlashAttention up to 2.8.3.post1 and classified as problematic. This affects the function download_and_copy of the file hopper/setup.py of the component Archive Extraction. Performing a manipulation results in symlink. This vulnerability is identified as CVE-2026-62239. The attack is only possible with local access. There is not any exploit available.

Detailsinfo

A vulnerability classified as problematic has been found in Dao-AILab FlashAttention up to 2.8.3.post1. This affects the function download_and_copy of the file hopper/setup.py of the component Archive Extraction. The manipulation with an unknown input leads to a symlink vulnerability. CWE is classifying the issue as CWE-61. The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-62239 since 07/13/2026. The exploitability is told to be easy. Attacking locally is a requirement. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• Dao-AILab

Name

• FlashAttention

Version

• 2.8.3.post1

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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