How severe is CVE-2025-66303?

CVE-2025-66303 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-2025-66303 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-2025-66303?

CVE-2025-66303 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-2025-66303?

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

Does CVE-2025-66303 have an EU (EUVD) identifier?

Yes. CVE-2025-66303 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200107.

When was CVE-2025-66303 published?

CVE-2025-66303 was published on 2025-12-01 and last updated on 2026-06-17.

CVE-2025-66303

CVE-2025-66303 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-400.

Key facts

Severity: Medium (CVSS 3.x base score 4.9)
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-200107
Weakness: CWE-400
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 has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27.

Frequently asked questions

What is CVE-2025-66303?: Grav is a file-based Web platform. Prior to 1.8.0-beta.27, A Denial of Service (DoS) vulnerability has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27.
How severe is CVE-2025-66303?: CVE-2025-66303 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-2025-66303 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-2025-66303?: CVE-2025-66303 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-2025-66303?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-66303 have an EU (EUVD) identifier?: Yes. CVE-2025-66303 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200107.
When was CVE-2025-66303 published?: CVE-2025-66303 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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