How severe is CVE-2025-2099?

CVE-2025-2099 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-2099 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-2099?

CVE-2025-2099 affects Huggingface Transformers. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-2099?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-2099 have an EU (EUVD) identifier?

Yes. CVE-2025-2099 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-15691.

When was CVE-2025-2099 published?

CVE-2025-2099 was published on 2025-05-19 and last updated on 2026-06-17.

CVE-2025-2099

CVE-2025-2099 is a high-severity vulnerability in Huggingface Transformers with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1333.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-15691
Weakness: CWE-1333
Affected product: Huggingface Transformers
Published: 2025-05-19
Last modified: 2026-06-17

Description

A vulnerability in the `preprocess_string()` function of the `transformers.testing_utils` module in huggingface/transformers version v4.48.3 allows for a Regular Expression Denial of Service (ReDoS) attack. The regular expression used to process code blocks in docstrings contains nested quantifiers, leading to exponential backtracking when processing input with a large number of newline characters. An attacker can exploit this by providing a specially crafted payload, causing high CPU usage and potential application downtime, effectively resulting in a Denial of Service (DoS) scenario.

Frequently asked questions

What is CVE-2025-2099?: A vulnerability in the `preprocess_string()` function of the `transformers.testing_utils` module in huggingface/transformers version v4.48.3 allows for a Regular Expression Denial of Service (ReDoS) attack. The regular expression used to process code blocks in docstrings contains nested quantifiers, leading to exponential backtracking when processing input with a large number of newline characters. An attacker can exploit this by providing a specially crafted payload, causing high CPU usage and potential application downtime, effectively resulting in a Denial of Service (DoS) scenario.
How severe is CVE-2025-2099?: CVE-2025-2099 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-2099 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-2099?: CVE-2025-2099 affects Huggingface Transformers. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-2099?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-2099 have an EU (EUVD) identifier?: Yes. CVE-2025-2099 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-15691.
When was CVE-2025-2099 published?: CVE-2025-2099 was published on 2025-05-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:huggingface:transformers:*:*:*:*:*:*:*:*

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