How severe is CVE-2025-66305?

CVE-2025-66305 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-66305 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-66305?

CVE-2025-66305 primarily affects Getgrav Grav. In total, 27 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-66305?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-66305 have an EU (EUVD) identifier?

Yes. CVE-2025-66305 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200105.

When was CVE-2025-66305 published?

CVE-2025-66305 was published on 2025-12-01 and last updated on 2026-06-17.

CVE-2025-66305

CVE-2025-66305 is a medium-severity vulnerability in Getgrav Grav with a CVSS 3.x base score of 4.9. 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-248.

Key facts

Severity: Medium (CVSS 3.x base score 4.9)
CVSS v4: 6.9
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-200105
Weakness: CWE-248
Affected product: Getgrav Grav
Published: 2025-12-01
Last modified: 2026-06-17

Description

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, a Denial of Service (DoS) vulnerability was identified in the "Languages" submenu of the Grav admin configuration panel (/admin/config/system). Specifically, the Supported parameter fails to properly validate user input. If a malformed value is inserted—such as a single forward slash (/) or an XSS test string—it causes a fatal regular expression parsing error on the server. This leads to application-wide failure due to the use of the preg_match() function with an improperly constructed regular expression, resulting in an error. Once triggered, the site becomes completely unavailable to all users. This vulnerability is fixed in 1.8.0-beta.27.

Frequently asked questions

What is CVE-2025-66305?: Grav is a file-based Web platform. Prior to 1.8.0-beta.27, a Denial of Service (DoS) vulnerability was identified in the "Languages" submenu of the Grav admin configuration panel (/admin/config/system). Specifically, the Supported parameter fails to properly validate user input. If a malformed value is inserted—such as a single forward slash (/) or an XSS test string—it causes a fatal regular expression parsing error on the server. This leads to application-wide failure due to the use of the preg_match() function with an improperly constructed regular expression, resulting in an error. Once triggered, the site becomes completely unavailable to all users. This vulnerability is fixed in 1.8.0-beta.27.
How severe is CVE-2025-66305?: CVE-2025-66305 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-66305 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66305?: CVE-2025-66305 primarily affects Getgrav Grav. In total, 27 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-66305?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-66305 have an EU (EUVD) identifier?: Yes. CVE-2025-66305 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200105.
When was CVE-2025-66305 published?: CVE-2025-66305 was published on 2025-12-01 and last updated on 2026-06-17.

References

Affected products (27)

cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta1:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta10:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta11:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta12:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta13:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta14:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta15:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta16:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta17:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta18:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta19:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta2:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta20:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta21:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta22:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta23:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta24:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta25:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta26:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta3:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta4:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta5:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta6:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta7:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta8:*:*:*:*:*:*
cpe:2.3:a:getgrav:grav:1.8.0:beta9:*:*:*:*:*:*

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