CVE-2025-66301 | Grav ihas Broken Access Control which allows an Editor to modify the page's YAML Frontmatter to alter form processing actions

Exp

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, due to improper authorization checks when modifying critical fields on a POST request to /admin/pages/{page_name}, an editor with only permissions to change basic content on the form is now able to change the functioning of the form through modifying the content of the data[_json][header][form] which is the YAML frontmatter which includes the process section which dictates what happens after a user submits the form which include some important actions that could lead to further vulnerabilities. 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-2025-66301 is rated High Exploit Risk (86.1/100): CVSS High severity, with high exploitation likelihood (EPSS 29.12%, 97th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.90% over the last day, indicating growing attacker interest. 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-2025-66301

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

Exploit prediction scoring system (EPSS) score for CVE-2025-66301

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 2026-05-21 26.22% 29.12% +2.90%
2 2026-04-30 26.93% 26.22% -0.71%
3 2026-04-29 — 26.93% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-66301

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 4.0 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:L)
Low privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H)
High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — [email protected]
9.6 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N 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:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.1 5.8 [email protected]

Weakness enumeration for CVE-2025-66301

GitHub Security Advisory for CVE-2025-66301

GHSA-v8x2-fjv7-8hjh · Severity: high · Ecosystem: composer — Grav has Broken Access Control which allows an Editor to modify the page's YAML Frontmatter to alter form processing actions

Affected software / configurations for CVE-2025-66301

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-2025-66301

cvelogic Threat Intelligence