CVE-2025-6638: Hugging Face Transformers vulnerable to ReDoS via MarianTokenizer
transformers, MarianTokenizer
Inefficient regular expression processing in the Hugging Face Transformers library enabled a denial of service via crafted inputs. The issue was fixed in version 4.53.0.
disclosed CVENo confirmed exploitation, so this record is tracked as a disclosed vulnerability and not counted as an incident. It moves into the counts if CISA or the vendor confirms exploitation. Why
- CVSS
- 5.3
- EPSS
- 0.01 · top 54% · 2026-11-13
- fix status
- Fix status unknown
- first report
- 12 Sep 2025
- last update
- 12 Sep 2025
- CVE ids
Timeline · 2
Sources · 2
Advisories and databases
- 2025-09-12CVE-2025-6638: Hugging Face Transformers is vulnerable to ReDoS through its MarianTokenizerGitHub Advisory Database · github.com/advisories/GHSA-59p9-h35m-wg4g
- 2025-09-12CVE-2025-6638: A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library,…NVD · nvd.nist.gov/vuln/detail/CVE-2025-6638
Titles and links belong to their publishers. The summary above is written by gcdRadar in its own words; data is CC BY-SA 4.0.
Classification
- lane
- Patch now
- AI role
- Attack on AI
- categories
- Infrastructure vulnerability
- severity
- 2 · Disclosed vulnerability
- fix status
- Fix status unknown
- targets
- Framework / tooling
- owasp llm top 10
- LLM03:2025 Supply Chain
- mitre atlas
- no technique for these categories
- dates
- happened 12 Sep 2025 · first reported 12 Sep 2025
- origin
- GitHub Advisory DatabaseVulnerability record from NVD / the GitHub Advisory Database. This product uses the NVD API but is not endorsed or certified by the NVD.
- record
- confidence 0.95 · created 2026-10-18 07:00Z · updated 2026-10-18 10:04Z
Lane, AI role, categories and severity come from the classifier; the OWASP and ATLAS rows are derived from the categories. How these are assigned
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the brief as text
# CVE-2025-6638: Hugging Face Transformers vulnerable to ReDoS via MarianTokenizer https://gcdradar.vercel.app/incidents/cve-2025-6638-hugging-face-transformers-vulnerable-to-redos · AIR-2025-0335 · closed 2025-09-12 - Lane: Patch now - Severity: 2 (Disclosed vulnerability) - Fix status: Fix status unknown - First reported: 2025-09-12 - AI role: Attack on AI - Products: transformers, MarianTokenizer - CVE ids: CVE-2025-6638 - CVSS: 5.3 ## Summary Inefficient regular expression processing in the Hugging Face Transformers library enabled a denial of service via crafted inputs. The issue was fixed in version 4.53.0. ## What to do No action recorded; read the sources below and the vendor's advisory. ## Latest updates - 2025-09-12: CVE-2025-6638: A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library,… (https://nvd.nist.gov/vuln/detail/CVE-2025-6638) - 2025-09-12: CVE-2025-6638: Hugging Face Transformers is vulnerable to ReDoS through its MarianTokenizer (https://github.com/advisories/GHSA-59p9-h35m-wg4g) ## Sources - 2025-09-12 GitHub Advisory Database: CVE-2025-6638: Hugging Face Transformers is vulnerable to ReDoS through its MarianTokenizer https://github.com/advisories/GHSA-59p9-h35m-wg4g - 2025-09-12 NVD: CVE-2025-6638: A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library,… https://nvd.nist.gov/vuln/detail/CVE-2025-6638 Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.
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