{"id":"PYSEC-2026-2477","summary":"flash-attention contains an insecure deserialization vulnerability in its checkpoint loading mechanism","details":"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.","aliases":["CVE-2026-31253","GHSA-7g5w-pq96-8c5w"],"modified":"2026-07-13T16:31:40.152625318Z","published":"2026-07-13T15:15:45.233345Z","references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31253"},{"type":"PACKAGE","url":"https://github.com/Dao-AILab/flash-attention"},{"type":"WEB","url":"https://www.notion.so/CVE-2026-31253-35d1e1393188813f9e77e2038104bc49"},{"type":"PACKAGE","url":"https://pypi.org/project/flash-attn"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-7g5w-pq96-8c5w"}],"affected":[{"package":{"name":"flash-attn","ecosystem":"PyPI","purl":"pkg:pypi/flash-attn"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2.8.3"}]}],"versions":["0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6.post1","0.2.7","0.2.8","1.0.0","1.0.1","1.0.2","1.0.3","1.0.3.post0","1.0.4","1.0.5","1.0.6","1.0.7","1.0.8","1.0.9","2.0.0.post1","2.0.1","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.0.6.post2","2.0.7","2.0.8","2.0.9","2.1.0","2.1.1","2.1.2.post3","2.2.0","2.2.1","2.2.2","2.2.3.post2","2.2.4","2.2.4.post1","2.2.5","2.3.0","2.3.1.post1","2.3.2","2.3.3","2.3.4","2.3.5","2.3.6","2.4.0.post1","2.4.1","2.4.2","2.4.3.post1","2.5.0","2.5.1.post1","2.5.2","2.5.3","2.5.4","2.5.5","2.5.6","2.5.7","2.5.8","2.5.9.post1","2.6.0.post1","2.6.1","2.6.2","2.6.3","2.7.0.post2","2.7.1.post4","2.7.2.post1","2.7.3","2.7.4.post1","2.8.0.post2","2.8.1","2.8.2","2.8.3"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/flash-attn/PYSEC-2026-2477.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"}]}