GHSA-4w7r-h757-3r74
Hugging Face Transformers vulnerable to Regular Expression Denial of Service (ReDoS) in the AdamWeightDecay optimizer
At a glance
- Published
- Updated
- CVE
- CVE-2025-6921
- Aliases
- PYSEC-2026-1980
- CVSS_V3
- CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Description
The huggingface/transformers library, versions prior to 4.53.0, is vulnerable to Regular Expression Denial of Service (ReDoS) in the AdamWeightDecay optimizer. The vulnerability arises from the _do_use_weight_decay method, which processes user-controlled regular expressions in the include_in_weight_decay and exclude_from_weight_decay lists. Malicious regular expressions can cause catastrophic backtracking during the re.search call, leading to 100% CPU utilization and a denial of service. This issue can be exploited by attackers who can control the patterns in these lists, potentially causing the machine learning task to hang and rendering services unresponsive.
Affected packages
| Package | Versions |
|---|---|
| PyPI · transformers | introduced 0, fixed 4.53.0 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-6921 ADVISORY
- https://github.com/huggingface/transformers/commit/47c34fba5c303576560cb29767efb452ff12b8be WEB
- https://github.com/huggingface/transformers/commit/d37f7517972f67e3f2194c000ed0f87f064e5099 WEB
- https://github.com/huggingface/transformers PACKAGE
- https://huntr.com/bounties/287d15a7-6e7c-45d2-8c05-11e305776f1f WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |