How severe is CVE-2025-58446?

CVE-2025-58446 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-2025-58446 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-58446?

CVE-2025-58446 affects Mlc-ai Xgrammar. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-58446?

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-2025-58446 have an EU (EUVD) identifier?

Yes. CVE-2025-58446 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-27083.

When was CVE-2025-58446 published?

CVE-2025-58446 was published on 2025-09-06 and last updated on 2026-06-17.

CVE-2025-58446

CVE-2025-58446 is a high-severity vulnerability in Mlc-ai Xgrammar 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-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.9
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-27083
Weakness: CWE-770
Affected product: Mlc-ai Xgrammar
Published: 2025-09-06
Last modified: 2026-06-17

Description

xgrammar is an open-source library for efficient, flexible, and portable structured generation. A grammar optimizer introduced in 0.1.23 processes large grammars (>100k characters) at very low rates, and can be used for DOS of model providers. This issue is fixed in version 0.1.24.

Frequently asked questions

What is CVE-2025-58446?: xgrammar is an open-source library for efficient, flexible, and portable structured generation. A grammar optimizer introduced in 0.1.23 processes large grammars (>100k characters) at very low rates, and can be used for DOS of model providers. This issue is fixed in version 0.1.24.
How severe is CVE-2025-58446?: CVE-2025-58446 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-2025-58446 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-58446?: CVE-2025-58446 affects Mlc-ai Xgrammar. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-58446?: 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-2025-58446 have an EU (EUVD) identifier?: Yes. CVE-2025-58446 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-27083.
When was CVE-2025-58446 published?: CVE-2025-58446 was published on 2025-09-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mlc-ai:xgrammar:0.1.23:*:*:*:*:*:*:*

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