How severe is CVE-2025-6507?

CVE-2025-6507 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-6507 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-6507?

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

Does CVE-2025-6507 have an EU (EUVD) identifier?

Yes. CVE-2025-6507 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-28743.

When was CVE-2025-6507 published?

CVE-2025-6507 was published on 2025-09-01 and last updated on 2026-06-17.

CVE-2025-6507

CVE-2025-6507 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 13% (96th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-28743
Weakness: CWE-502
Published: 2025-09-01
Last modified: 2026-06-17

Description

A vulnerability in the h2oai/h2o-3 repository allows attackers to exploit deserialization of untrusted data, potentially leading to arbitrary code execution and reading of system files. This issue affects the latest master branch version 3.47.0.99999. The vulnerability arises from the ability to bypass regular expression filters intended to prevent malicious parameter injection in JDBC connections. Attackers can manipulate spaces between parameters to evade detection, allowing for unauthorized file access and code execution. The vulnerability is addressed in version 3.46.0.8.

Frequently asked questions

What is CVE-2025-6507?: A vulnerability in the h2oai/h2o-3 repository allows attackers to exploit deserialization of untrusted data, potentially leading to arbitrary code execution and reading of system files. This issue affects the latest master branch version 3.47.0.99999. The vulnerability arises from the ability to bypass regular expression filters intended to prevent malicious parameter injection in JDBC connections. Attackers can manipulate spaces between parameters to evade detection, allowing for unauthorized file access and code execution. The vulnerability is addressed in version 3.46.0.8.
How severe is CVE-2025-6507?: CVE-2025-6507 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-6507 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-6507?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-6507 have an EU (EUVD) identifier?: Yes. CVE-2025-6507 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-28743.
When was CVE-2025-6507 published?: CVE-2025-6507 was published on 2025-09-01 and last updated on 2026-06-17.

References

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