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.
History

Tue, 12 May 2026 20:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-94
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 12 May 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Dao-ailab
Dao-ailab flash-attention
Vendors & Products Dao-ailab
Dao-ailab flash-attention

Mon, 11 May 2026 18:00:00 +0000

Type Values Removed Values Added
Title Insecure Deserialization in flash‑attention Checkpoint Loading Allows Arbitrary Code Execution
Weaknesses CWE-502

Mon, 11 May 2026 16:30:00 +0000

Type Values Removed Values Added
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.
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2026-05-11T00:00:00.000Z

Updated: 2026-05-12T19:32:41.020Z

Reserved: 2026-03-09T00:00:00.000Z

Link: CVE-2026-31253

cve-icon Vulnrichment

Updated: 2026-05-12T19:32:36.406Z

cve-icon NVD

Status : Deferred

Published: 2026-05-11T17:16:20.307

Modified: 2026-05-12T20:16:34.110

Link: CVE-2026-31253

cve-icon Redhat

No data.