Skip to main content

grav-plugin-api CVE-2026-80203

| EUVDEUVD-2026-66394 CRITICAL
Incorrect Authorization (CWE-863)
2026-08-26 VulnCheck GHSA-jqh9-6gqv-p52m
9.3
CVSS 4.0 · Vendor: VulnCheck
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Obtain scoped key on super-admin account
  2. Delivery
    Reach plugin API over network
  3. Exploit
    Call requireNotSuperTarget endpoint
  4. Execution
    Bypass scope via isSuperAdmin check
  5. Persist
    Mint key / disable victim 2FA
  6. Impact
    Take over super-admin account

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Authorization logic validation
MITRE ATT&CK

1 technique across 1 tactic: Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Exploitation requires possession of a valid grav-plugin-api API key that belongs to a super-admin account but is scoped below full super authority, and the target Grav instance must run the plugin at a version before 1.0.18 with the API reachable by the attacker. The bug is triggered against the seven user-management endpoints guarded by requireNotSuperTarget() in UsersController.php. Limiting factors: the attacker cannot succeed with an ordinary non-super account's key (the account must itself be super-admin), so this is fundamentally a scope-escalation from an already-privileged credential rather than open unauthenticated access, which meaningfully narrows the realistic attacker set to insiders or those who have stolen such a key. No user interaction is required.

Impact

The supplied CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H) scores 9.3, but PR:N conflicts with the description, which plainly requires the attacker to already hold a valid API key belonging to a super-admin account-i.e., meaningful prior privilege. Treat this as an authenticated privilege/scope-escalation issue (PR:L in my independent assessment), not a fully unauthenticated RCE-class flaw; the network vector and low complexity are accurate, and impact is genuinely high once the precondition is met. There is no CISA KEV listing and no POC/exploit signal in the provided data, and no EPSS score was supplied, so real-world exploitation pressure appears low-to-moderate and gated by insider or credential-compromise scenarios. Bottom line: high technical impact but a real precondition (possession of a super-admin account's scoped key), so prioritize patching for any Grav install exposing this API, while recognizing it is less broadly weaponizable than the raw 9.3 implies.

Exploit ScenarioDerived

An operator issues a deliberately down-scoped API key under a super-admin account for a limited automation task; an attacker who obtains that key (or a malicious insider holding it) calls the affected user-management endpoints to disable another super-admin's 2FA and mint a new API key under that victim's identity, achieving full account takeover. Because the vector is network-based with low complexity, the actions are simple authenticated HTTP requests once the key is in hand; no public POC is identified in the provided data.

Act Now Prioritize within 24-48h. Why: CRITICAL severity.
Patch available 0.4% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Aug 26, 2026

Broken authorization in getgrav/grav-plugin-api before 1.0.18 lets a scoped API key that belongs to a super-admin account perform privileged user-management actions it was never scoped for. Across seven sensitive endpoints the requireNotSuperTarget() guard in UsersController.php checks isSuperAdmin() on the underlying account instead of whether the presented key carries super authority (isSuperWithinScope()), so a deliberately down-scoped key can act against other super-admin accounts-disabling their 2FA, deleting avatars, and minting or deleting their API keys. Reported by VulnCheck; no public exploit identified at time of analysis, and it is not on CISA KEV.

RemediationAI

Upgrade grav-plugin-api to version 1.0.18 or later, which corrects requireNotSuperTarget() to evaluate the presented key's authority via isSuperWithinScope() rather than the account's isSuperAdmin() role (see GHSA-94q7-vrqr-cx5v). If you cannot patch immediately, treat every existing API key tied to a super-admin account as effectively super-privileged and rotate or revoke down-scoped keys that were assumed safe; restrict network access to the plugin's API endpoints (for example via reverse-proxy allowlisting or firewalling the API paths) so only trusted callers can reach the seven user-management routes, accepting that this may break legitimate automation using those keys. As a stronger interim control, avoid issuing scoped keys under super-admin accounts at all-provision automation against lower-privilege accounts-so that even a scope bypass cannot reach super-admin targets.

Affected VersionsENISA

grav 0 <1.0.18

Affected Packages

euvd grav fix: 1.0.18

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Grav is a PHP flat-file CMS, and grav-plugin-api exposes an HTTP API with scoped API keys intended to limit what each key can do even when it is tied to a highly privileged account. The flaw is a CWE-863 (Incorrect Authorization) scope-confusion bug: requireNotSuperTarget() authorizes based on the account's role (isSuperAdmin()) rather than the effective authority of the specific credential presented, so the key-scoping layer (isSuperWithinScope()) is bypassed. This is a classic conflation of 'who owns this key' with 'what is this key allowed to do,' collapsing the least-privilege boundary that scoped keys are supposed to enforce. Affected code path: UsersController.php, seven user-management endpoints, fixed in plugin release 1.0.18.

Know when Grav gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (VulnCheck) PRIMARY 9.3 CRITICAL
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
vuln.today AI 8.8 HIGH

Network low-complexity attack but requires a valid super-admin-owned scoped API key, so PR:L not PR:N; full compromise of targeted accounts gives C:H/I:H/A:H within the app scope.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
High
Vulnerable system: Availability
High
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

Lifecycle Timeline

2
Patch available
Aug 26, 2026 - 12:02 EUVD
CVE Published
Aug 26, 2026 - 10:28 cve.org
CRITICAL 9.3

DescriptionCVE.org

The getgrav/grav-plugin-api plugin before 1.0.18 does not enforce API-key scope in the requireNotSuperTarget() function in UsersController.php across seven sensitive user-management endpoints. The check uses isSuperAdmin() on the acting account rather than verifying whether the specific API key carries super authority (via isSuperWithinScope()). As a result, an API key scoped below full super authority but belonging to a super-admin account can act against other super-admin accounts-disabling their 2FA, deleting their avatar, minting new API keys under their identity, or deleting their existing API keys.

Executive ViewAI

Why It Matters

The Grav plugin API (versions before 1.0.18) contains a critical authorization flaw that allows attackers with scoped API credentials to bypass restrictions and gain unauthorized control over super-admin accounts, including disabling 2FA and revoking administrative access. Organizations using this plugin face immediate risk of account takeover affecting their most privileged users and potential lateral privilege escalation throughout API-managed infrastructure. This vulnerability impacts any deployment relying on the Grav plugin API for user or account management.

Business Impact: Severe
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: enforce network-level API access restrictions via firewall (internal-only or trusted IPs); minimize or disable API key usage for super-admin accounts; implement real-time logging and alerting on API key usage and modifications to super-admin account settings; require manual authorization for all sensitive admin operations; and consider disabling the API plugin entirely if not actively required until a patch is available.

Threat Intelligence Overview

EPSS Score
0.4%
Top 68% exploitable
Prevalence
Low
niche API add-on for a modestly popular flat-file PHP CMS
Social Media
1
Sightings
Data Quality
6 sources
Confidence: High

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC No
EPSS 0.4%
Patch available Yes
Active threat No
Deciding rule
CRITICAL severity
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Out-of-Cycle
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact
Very High

Priority Score

46
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +46
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

More in Grav

View all
CVE-2025-66294 HIGH POC
8.7 Dec 01

Server-side template injection (SSTI) in Grav (getgrav/grav) prior to 1.8.0-beta.27 allows an authenticated attacker hol

CVE-2025-66301 HIGH POC
8.6 Dec 01

Broken access control in Grav CMS (CWE-285) before 1.8.0-beta.27 lets an authenticated editor-level user escalate their

CVE-2025-50286 HIGH POC
8.1 Aug 06

A Remote Code Execution (RCE) vulnerability in Grav CMS v1.7.48 allows an authenticated admin to upload a malicious plug

CVE-2024-34082 CRITICAL POC
9.9 May 15

Grav is a file-based Web platform. Rated critical severity (CVSS 9.9), this vulnerability is remotely exploitable, low a

CVE-2021-47812 CRITICAL POC
9.8 Jan 16

GravCMS 1.10.7 allows unauthenticated remote attackers to write arbitrary YAML configuration files, leading to full serv

CVE-2026-65008 CRITICAL POC
9.3 Jul 21

Remote code execution in Grav CMS 2.0.4 (fixed in 2.0.7) lets an authenticated user holding the admin.pages or api.pages

CVE-2026-75827 CRITICAL POC
9.3 Aug 18

Remote code execution in Grav CMS before 2.0.15 allows attackers holding page-edit or blueprint-config privileges to wri

CVE-2026-75837 CRITICAL POC
9.3 Aug 18

Vertical privilege escalation in Grav CMS before 2.0.14 lets a delegated administrator holding only the admin.users perm

CVE-2026-75828 CRITICAL POC
9.3 Aug 18

Stored cross-site scripting in Grav CMS before 2.0.15 lets authenticated editors smuggle JavaScript event handlers past

CVE-2025-66844 CRITICAL POC
9.1 Dec 15

Server-side request forgery (SSRF) in Grav CMS versions prior to 1.7.49.5 allows remote authenticated attackers to make

CVE-2025-66299 HIGH POC
8.8 Dec 01

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, Grav CMS is vulnerable to a Server-Side Template Injection (S

CVE-2026-72819 HIGH POC
8.7 Aug 14

Remote code execution in Grav CMS before 2.0.13 allows authenticated low-privilege users to plant and execute arbitrary

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy