CVE-2026-85670
- Source
- https://cve.org/CVERecord?id=CVE-2026-85670
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-85670.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-85670
- Published
- 2026-09-04T14:32:25.391Z
- Modified
- 2026-09-06T03:47:20.256899663Z
- Severity
-
- 7.1 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- tokenizers BpeBuilder Buffer Overflow via merge token
- Details
-
tokenizers (Hugging Face) is affected by an out-of-bounds buffer access in BpeBuilder::build (tokenizers/src/models/bpe/model.rs). When loading a tokenizer.json via Tokenizer::fromfile/fromstr, the builder sizes a scratch buffer to the longest vocabulary key, then writes each concatenated merge rule into it. A merge whose concatenated token exceeds the longest vocabulary key overruns the buffer, which Rust turns into a panic that aborts the process in Rust and FFI embeddings. This occurs at load time with no encoding required, so an attacker who supplies a crafted tokenizer.json can cause a denial of service. A secondary defect at the same location can cause a usize underflow (panic in debug, potential memory corruption in release) when continuingsubwordprefix is set and a merge token is shorter than the prefix. Observed in version 0.23.1.
- Database specific
{ "cwe_ids": [ "CWE-787" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85670.json", "cna_assigner": "VulnCheck" }- References
-
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85670.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-85670
- https://www.vulncheck.com/advisories/tokenizers-bpebuilder-buffer-overflow-via-merge-token
- https://github.com/huggingface/tokenizers/issues/2094
- https://github.com/huggingface/tokenizers
- https://github.com/huggingface/tokenizers/blob/v0.23.2/tokenizers/src/models/bpe/model.rs