CVE-2026-31253

HIGH

flash-attention thru e724e2588c - Deserialization

Title source: llm
STIX 2.1

Description

The flash-attention training framework thru commit e724e2588cbe754beb97cf7c011b5e7e34119e62 (2025-13-04) contains an insecure deserialization vulnerability (CWE-502) in its checkpoint loading mechanism. The load_checkpoint() function in checkpoint.py and the checkpoint loading code in eval.py use torch.load() without enabling the security-restrictive weights_only=True parameter. This allows the deserialization of arbitrary Python objects via the pickle module. An attacker can exploit this by providing a maliciously crafted checkpoint file. When a victim loads this checkpoint during model warmstarting or evaluation, arbitrary code is executed on the victim's system.

Scores

CVSS v3 7.3
EPSS 0.0005
EPSS Percentile 14.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-502 CWE-94
Status published
Products (1)
pypi/flash_attn 0 - 2.8.3PyPI
Published May 11, 2026
Tracked Since May 11, 2026