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GL.iNet Routers CVE-2026-19979

| EUVDEUVD-2026-60039 MEDIUM
Authorization Bypass Through User-Controlled Key (CWE-639)
2026-08-17 VulDB GHSA-39pc-4mfv-4php
6.9
CVSS 4.0 · Vendor: VulDB
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Attack ChainAIDerived

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

  1. Access
    Identify WAN-exposed WebDAV endpoint
  2. Delivery
    Send COPY/MOVE with crafted unauthorized destination path
  3. Exploit
    Bypass destination authorization check
  4. Execution
    Write or relocate files to protected filesystem location
  5. Impact
    Leverage misplaced file for persistence or information disclosure

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Object-level authorization, IDOR prevention
Exploitation Conditions

The GL.iNet WebDAV service must be enabled on the router (it is a configurable feature, not necessarily on by default - verify per model/firmware). A public share (unauthenticated WebDAV share) must be configured, as the bypass is specifically described as a 'Public-Share Destination Authorization Bypass,' implying the unauthenticated public share context is where the flaw manifests. Network reachability to the WebDAV service port is required; exploitation is most severe when the WebDAV listener is reachable from the WAN. Exploitation is limited by: devices where WebDAV is disabled (eliminates risk entirely); devices where no public unauthenticated share is configured (reduces or eliminates the unauthenticated attack path); and devices where the WebDAV port is firewalled to LAN-only access (constrains attacker position to internal network). Authentication requirements are not confirmed beyond what the CVSS 4.0 PR:N vector implies.

Impact

The CVSS 4.0 base score of 6.9 with AV:N/AC:L/AT:N/PR:N/UI:N reflects a low-complexity, unauthenticated, network-reachable attack - real-world risk is therefore elevated relative to the moderate numerical score. All three impact axes (VC:L/VI:L/VA:L plus SC:L/SI:L/SA:L) are Low rather than High, which appropriately constrains the score: the bypass grants partial file system access outside the public share, not full device compromise or credential exposure. EPSS data is not available in the provided intelligence, limiting quantitative exploitation probability assessment. No CISA KEV listing exists, and no public exploit code is identified, suggesting opportunistic mass exploitation is not yet occurring. The E:X modifier in the CVSS 4.0 vector indicates exploitation evidence is undefined rather than confirmed absent. The most significant real-world risk factor is that GL.iNet routers are frequently deployed in network-edge positions where WebDAV may be WAN-exposed by design (travel router use case). A low-complexity, unauthenticated path bypass against a publicly reachable service is a realistic exploitation scenario even absent a weaponized tool. Defenders should treat this as a medium-priority fix, elevated to high priority on devices with WAN-facing WebDAV.

Exploit ScenarioDerived

An attacker who can reach the GL.iNet router's WebDAV endpoint - either over the internet if the service is WAN-exposed, or from the local network - issues a WebDAV COPY or MOVE HTTP request targeting a file within the public share as the source, but specifying a path outside the authorized share (such as /etc or a private storage directory) as the destination. The firmware's authorization check validates the source access but fails to enforce access control on the destination path, allowing the file to be placed in the protected location. No exploit code is publicly confirmed, but the attack requires only standard WebDAV HTTP methods available in curl or any WebDAV client.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.4% exploitation probability (EPSS)

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AnalysisAIv1 – Aug 17, 2026

Authorization bypass in the WebDAV Service COPY/MOVE operations on seventeen GL.iNet router models running firmware up to 4.8.x allows remote unauthenticated attackers to read and write files outside their authorized share boundaries. The root cause, per the GitHub reference title 'WebDAV Public-Share Destination Authorization Bypass', is that the destination path supplied in COPY/MOVE requests is not properly authorization-checked against the caller's access scope - a classic CWE-639 user-controlled key bypass. The vendor has independently confirmed the vulnerability exists. No public exploit code or CISA KEV listing is identified at time of analysis.

RemediationAI

No specific patched firmware version is confirmed from the available data; check the vendor's CVE issues repository at https://github.com/gl-inet/CVE-issues/blob/main/4.0.0/WebDAV%20Public-Share%20Destination%20Authorization%20Bypass.md and the GL.iNet firmware release page for an updated build that addresses CVE-2026-19979. As an immediate compensating control, disable the WebDAV service entirely via the router's LuCI/GL.iNet admin interface if file sharing is not required - this eliminates the attack surface with no security trade-off for most deployments. If WebDAV is operationally required, restrict its listener to the LAN interface only and block WAN-side access via firewall rules, preventing remote exploitation while preserving local functionality; note this does not protect against attacks originating from a compromised LAN host. Additionally, consider removing public (unauthenticated) WebDAV share configurations until a patch is applied, forcing all WebDAV access through authenticated sessions, which significantly raises the bar even if the destination authorization bypass itself is unpatched.

Affected VersionsENISA

MT3000 4.7
MT5000 4.0
MT6000 4.6
BE1400 4.3
X2000 4.4
AXT1800 4.2
E5800 4.5
MT6000 4.5
BE3600 4.4
MT3600BE 4.4
E5800 4.1
XE3000 4.4
BE9300 4.4
AX1800 4.8
MT6000 4.2
AXT1800 4.6
A1300 4.0
BE6500 4.4
MT5000 4.3
E5800 4.6
BE6500 4.6
XE3000 4.2
BE1400 4.5
A1300 4.4
MT3600BE 4.2
BE3600 4.8
BE9300 4.3
AX1800 4.0
BE9300 4.0
X3000 4.6
BE9300 4.5
BE9300 4.1
MT3000 4.4
A1300 4.7
AX1800 4.6
AXT1800 4.0
BE6500 4.3
MT5000 4.5
X2000 4.8
X2000 4.1
AXT1800 4.3
MT3000 4.1
BE10000 4.8
AXT1800 4.1
E5800 4.4
BE3600 4.6
XE3000 4.5
AXT1800 4.5
A1300 4.2
MT3000 4.2
MT2500 4.3
AXT1800 4.4
A1300 4.5
BE10000 4.3
MT6000 4.0
BE9300 4.7
BE1400 4.8
MT2500 4.6
BE3600 4.7
E5800 4.2
MT3000 4.8
X2000 4.2
BE10000 4.5
AXT1800 4.7
MT5000 4.6
BE10000 4.1
XE3000 4.1
X3000 4.0
BE3600 4.1
BE6500 4.8
XE3000 4.6
MT2500 4.8
BE10000 4.0
AX1800 4.4
BE6500 4.2
XE3000 4.3
MT6000 4.1
MT5000 4.1
AX1800 4.5
X2000 4.3
MT5000 4.2
MT2500 4.1
MT2500 4.0
AX1800 4.3
MT6000 4.4
X3000 4.1
X3000 4.4
E5800 4.8
MT3000 4.0
BE9300 4.2
MT3000 4.3
BE10000 4.4
MT3000 4.6
AX1800 4.7
BE6500 4.7
MT3600BE 4.5
BE10000 4.7
BE1400 4.2
BE3600 4.2
BE6500 4.5
X3000 4.5
BE1400 4.6
X2000 4.5
MT3600BE 4.6
A1300 4.1
XE3000 4.8
XE3000 4.7
MT3600BE 4.0
AX1800 4.1
BE1400 4.1
E5800 4.0
MT2500 4.5
MT2500 4.2
XE3000 4.0
BE1400 4.4
X2000 4.7
MT5000 4.7
BE10000 4.2
MT5000 4.4
BE6500 4.0
BE3600 4.5
MT3000 4.5
MT3600BE 4.3
X3000 4.2
BE9300 4.8
MT6000 4.3
MT2500 4.7
MT6000 4.8
A1300 4.3
MT3600BE 4.8
MT3600BE 4.1
BE3600 4.3
MT2500 4.4
E5800 4.3
BE1400 4.7
X3000 4.3
A1300 4.6
AXT1800 4.8
BE9300 4.6
E5800 4.7
A1300 4.8
X2000 4.6
MT3600BE 4.7
X2000 4.0
BE3600 4.0
BE10000 4.6
BE1400 4.0
X3000 4.8
X3000 4.7
BE6500 4.1
MT5000 4.8
MT6000 4.7
AX1800 4.2

Affected Packages

euvd a1300 no fix
euvd ax1800 no fix
euvd axt1800 no fix
euvd be10000 no fix
euvd be1400 no fix
euvd be3600 no fix
euvd be6500 no fix
euvd be9300 no fix
euvd e5800 no fix
euvd mt2500 no fix
euvd mt3000 no fix
euvd mt3600be no fix
euvd mt5000 no fix
euvd mt6000 no fix
euvd x2000 no fix
euvd x3000 no fix
euvd xe3000 no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 17 packages in euvd

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

Technical ContextAI · show details

GL.iNet manufactures a broad line of travel and specialty routers running their proprietary OpenWrt-derived firmware. The affected component is the embedded WebDAV service, which implements HTTP extension methods (RFC 4918) including COPY and MOVE for remote file management - commonly used for NAS-style file sharing on the router's attached storage. CWE-639 (Authorization Bypass Through User-Controlled Key) identifies the root cause: the WebDAV implementation uses a caller-supplied destination path as the access-control key without validating whether the requesting party holds authorization for that destination. An attacker targeting a public share can craft a COPY or MOVE request with a destination pointing to a protected filesystem location, and the service fails to enforce the boundary. Affected CPEs span the full current product line: cpe:2.3:a:gl.inet:a1300, ax1800, axt1800, be1400, be3600, be6500, be9300, be10000, e5800, mt2500 (and mt3000, mt3600be, mt5000, mt6000, x2000, x3000, xe3000 per description), all at wildcard versions up to 4.8.x.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (VulDB) PRIMARY 6.9 MEDIUM
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L
vuln.today AI 7.2 HIGH

Network-accessible public WebDAV share requires no privileges; scope changes as files escape the authorized share boundary into protected filesystem locations; no availability impact described.

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

Primary rating from Vendor (VulDB).

CVSS VectorVendor: VulDB

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

DescriptionCVE.org

A vulnerability was identified in GL.iNet A1300, AX1800, AXT1800, BE1400, BE3600, BE6500, BE9300, BE10000, E5800, MT2500, MT3000, MT3600BE, MT5000, MT6000, X2000, X3000 and XE3000 up to 4.8.x. Affected by this vulnerability is the function COPY/MOVE of the component WebDAV Service. Such manipulation leads to authorization bypass. It is possible to launch the attack remotely. The vendor explains: "After our investigation, we have confirmed that the vulnerability described (...) does indeed exist."

Threat Intelligence Overview

EPSS Score
0.4%
Top 68% exploitable
Prevalence
Medium
popular privacy/travel router brand, broad consumer and prosumer footprint
Social Media
2
Sightings
Data Quality
7 sources
Confidence: High
EUVD NVD CVE.org EPSS Vulnrichment CIRCL GitHub VulDB

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 MEDIUM
CISA KEV No
Public POC No
EPSS 0.4%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
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
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
Yes
Human Impact· derived
Medium
Technical Impact
Partial

Priority Score

34
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +34
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.

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