CVE-2025-66303 | Grav is vulnerable to a DOS on the admin panel

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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.

Published: 2025-12-01 Last update: 2025-12-03 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-66303 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.33%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2025-66303

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2025-66303

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.12% 0.33% +0.21%
2 2026-04-29 0.16% 0.12% -0.04%
3 2026-04-02 — 0.16% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-66303

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.2 3.6 [email protected]

Weakness enumeration for CVE-2025-66303

GitHub Security Advisory for CVE-2025-66303

GHSA-x62q-p736-3997 · Severity: medium · Ecosystem: composer — Grav is vulnerable to a DOS on the admin panel

Affected software / configurations for CVE-2025-66303

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

References for CVE-2025-66303

cvelogic Threat Intelligence