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CVE Record

CVE-2026-72699: Grav Login Plugin before 3.9.1 Email Enumeration via Registration

The Grav Login plugin (getgrav/grav-plugin-login) before 3.9.1 is vulnerable to email address enumeration. The register() method in classes/Login.php throws a distinct exception (EMAIL_NOT_AVAILABLE) when a submitted email address already belongs to an existing account, while allowing registration to proceed otherwise. Because the registration endpoint has no rate limiting, an attacker can enumerate which email addresses have accounts on the site, one guess per request.

CriticalCVSS 9.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

Public registration can reveal whether an email address belongs to an existing Grav account because the Login plugin responds differently for registered and unregistered addresses. Attackers could remotely build user lists for phishing, credential attacks, or privacy abuse. The supplied sources do not establish direct account compromise.

Executive priority

Prioritize prompt remediation on public-facing sites with registration enabled. The reported critical score warrants urgency, but the demonstrated behavior is email enumeration rather than confirmed account compromise. Reduce exposure immediately where upgrades cannot be completed promptly.

Technical view

Grav Login plugin versions before 3.9.1 expose an observable registration response difference. Login.php register() raises EMAIL_NOT_AVAILABLE for an existing address but permits other registrations. Unauthenticated, low-complexity requests can test addresses individually, and the registration endpoint lacks rate limiting. This is classified as CWE-203.

Likely exposure

Internet-accessible Grav sites are likely exposed when they run Login plugin versions earlier than 3.9.1 and enable public registration. Sites without the plugin, running 3.9.1 or later, or without a reachable registration function are not shown as affected by this bundle.

Exploitation context

Enumeration requires no authentication or user interaction and can be performed remotely, one address per request. Missing rate limiting increases practical scalability. The bundle reports no KEV listing and provides no evidence of active exploitation; enumeration should not be represented as proven account takeover.

Researcher notes

The bundle assigns CVSS 4.0 score 9.3 with high vulnerable-system confidentiality, integrity, and availability impacts. Its described mechanism directly supports account-email disclosure, but does not explain those broader impacts. Validate version boundaries, registration configuration, response equivalence, and throttling. Do not infer active exploitation from severity alone.

Mitigation direction

  • Upgrade the Grav Login plugin to version 3.9.1 or later.
  • Follow the vendor advisory and verify any deployment-specific upgrade requirements.
  • Restrict or disable public registration until upgrading if business operations permit.
  • Apply rate limiting and monitoring to registration requests as defense in depth.

Validation and detection

  • Inventory Grav installations and record the installed Login plugin version.
  • Confirm whether public registration is enabled and reachable from untrusted networks.
  • Verify registration responses do not distinguish existing from unregistered email addresses.
  • Review registration logs for repeated address testing, high request volume, or distributed probing.
  • Confirm rate limiting works without exposing different responses for known accounts.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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cwe · medium confidence lookup

CWE-203: Information exposure and cloud metadata lookup

Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2026-72699 mapping review

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.3 (4.0)
Known Exploited
No
Published

Vector: 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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
3Timeline events
1ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.3CVSS 4.0CriticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——VulnCheck
5.3CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N3.91.4VulnCheck

Vulnerability scoring details

Base CVSS 4.0 score

9.3Critical
CVSS 4.0 vector shape for CVE-2026-72699Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: 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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
getgravgrav-plugin-login0, 3.9.1unaffected
Weakness

CWE details

CWE-203

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-203 · source CWE mapping

CWE mapping pending import

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