{"cve":"CVE-2026-31253","nvd":{"published":"2026-05-11T17:16:20.307","modified":"2026-06-17T10:33:32.820","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","score":7.3},"cwes":["CWE-94","CWE-502"],"references":["https://github.com/Dao-AILab/flash-attention","https://www.notion.so/CVE-2026-31253-35d1e1393188813f9e77e2038104bc49"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:33:55.586217763+00:00"},"epss":{"cve":"CVE-2026-31253","score":0.00218,"percentile":0.12341,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-7g5w-pq96-8c5w","url":"https://osv.dev/vulnerability/GHSA-7g5w-pq96-8c5w","summary":"flash-attention contains an insecure deserialization vulnerability in its checkpoint loading mechanism","modified":"2026-07-14T05:30:20.366472231Z","packages":[{"ecosystem":"PyPI","name":"flash-attn","purl":"pkg:pypi/flash-attn","ranges":["<=2.8.3"],"fixed":[]}]},{"id":"PYSEC-2026-2477","url":"https://osv.dev/vulnerability/PYSEC-2026-2477","summary":"flash-attention contains an insecure deserialization vulnerability in its checkpoint loading mechanism","modified":"2026-07-13T16:31:40.152625318Z","packages":[{"ecosystem":"PyPI","name":"flash-attn","purl":"pkg:pypi/flash-attn","ranges":["<=2.8.3"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}