Vulnerability · CVE-2025-3263
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically in the function within the module.
Published Jul 7, 2025 · catalog updated Jul 7, 2025 · A Regular Expression Denial
Last checked Nov 4, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2025-3263. EPSS is 0.50%. Act only if a listed version of A Regular Expression Denial is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (A Regular Expression Denial).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2025-6921 · Medium
- CVE-2025-6051 · Medium
- CVE-2025-6638 · Medium
- CVE-2025-5197 · Medium
- CVE-2025-3933 · Medium
- Severity
- Medium5.3
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.50%
- Remediation
- Version ranges on file
- Affected products
- vendor huggingface huggingface/transformers unspecified <4.51.0
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically in the function within the module. The affected version is 4.49.0, and the issue is resolved in version 4.51.0. The vulnerability arises from the use of a regular expression pattern that can be exploited to cause excessive CPU consumption through crafted input strings, leading to catastrophic backtracking. This can result in model serving disruption, resource exhaustion, and increased latency in applications using the library.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor huggingface huggingface/transformers unspecified <4.51.0unspecified <4.51.0
How to fix CVE-2025-3263
Upgrade
CVE-2025-3263 lists a fix boundary at 4.51.0. Compare the installed build with that boundary before you change production.
Version check
Seen in unspecified <4.51.0
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2025-3263. EPSS is 0.50%. Act only if a listed version of A Regular Expression Denial is installed.
Which versions are affected?
Compare what you have installed with huggingface huggingface/transformers unspecified <4.51.0 unspecified <4.51.0. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.50%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Jul 7, 2025 · EUVD
Detected
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically in the function within the module. The affected version is 4.49.0, and the issue is resolved in version 4.51.0. The vulnerability arises from the use of a regular expression pattern that can be exploited to cause excessive CPU consumption through crafted input strings,
Jul 7, 2025 · EUVD
Updated
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically in the function within the module. The affected version is 4.49.0, and the issue is resolved in version 4.51.0. The vulnerability arises from the use of a regular expression pattern that can be exploited to cause excessive CPU consumption through crafted input strings,
Sources
- CVE.orgVulnerability recordCVE-2025-3263
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2025-3263
30-day exploitation probability 0.50%
first.org - EUVDVulnerability recordEUVD-2025-20215
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically in the function within the module. The affected version is 4.49.0, and the issue is resolved in version 4.51.0. The vulnerability arises from the use
euvd.enisa.europa.eu
References
Freshness
Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSOct 23, 2026
- CVE.orgOct 21, 2026
- EUVDOct 20, 2026