{"id":"PYSEC-2026-1979","summary":"Transformers vulnerable to ReDoS attack through its SETTING_RE variable","details":"A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the huggingface/transformers repository, specifically in version 4.49.0. The vulnerability is due to inefficient regular expression complexity in the `SETTING_RE` variable within the `transformers/commands/chat.py` file. The regex contains repetition groups and non-optimized quantifiers, leading to exponential backtracking when processing 'almost matching' payloads. This can degrade application performance and potentially result in a denial-of-service (DoS) when handling specially crafted input strings. The issue is fixed in version 4.51.0.","aliases":["CVE-2025-3262","GHSA-489j-g2vx-39wf"],"modified":"2026-07-07T17:48:13.616945161Z","published":"2026-07-07T16:02:56.726858Z","references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-3262"},{"type":"WEB","url":"https://github.com/huggingface/transformers/commit/0720e206c6ba28887e4d60ef60a6a089f6c1cc76"},{"type":"WEB","url":"https://github.com/huggingface/transformers/commit/126abe3461762e5fc180e7e614391d1b4ab051ca"},{"type":"PACKAGE","url":"https://github.com/huggingface/transformers"},{"type":"WEB","url":"https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184"},{"type":"PACKAGE","url":"https://pypi.org/project/transformers"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-489j-g2vx-39wf"}],"affected":[{"package":{"name":"transformers","ecosystem":"PyPI","purl":"pkg:pypi/transformers"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.49.0"},{"fixed":"4.51.0"}]}],"versions":["4.49.0","4.50.0","4.50.1","4.50.2","4.50.3"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/transformers/PYSEC-2026-1979.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:N/I:N/A:L"}]}