Security readout for executives and security teams
Plain-English summary
A command-injection flaw in GL.iNet AX1800 firmware could let an authenticated remote user make the router execute unintended system commands through its RPC service. Successful abuse could compromise data, configuration, and availability. Public exploit material increases urgency, although the supplied evidence does not establish active exploitation.
Executive priority
Prioritize this urgently because command injection could permit full device compromise and public exploit material exists. Immediately inventory and isolate affected routers while obtaining vendor remediation guidance. Do not characterize this as active exploitation without new evidence.
Technical view
CVE-2026-18787 affects the remove_rule function in /usr/share/gl-ngx/oui-rpc.lua. Manipulating args.id causes command injection, classified as CWE-74 and CWE-77. The listed affected firmware versions are 4.8.0 through 4.8.3. The CVSS 2.0 vector indicates network reachability, low complexity, required authentication, and complete confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to GL.iNet AX1800 devices running firmware 4.8.0, 4.8.1, 4.8.2, or 4.8.3. Practical risk depends on whether the RPC or management interface is reachable and whether an attacker can obtain authenticated access. The bundle does not establish that all affected devices are internet-accessible.
Exploitation context
Public exploit material is referenced, demonstrating disclosure beyond a theoretical report. However, the bundle marks KEV as false and supplies no evidence of observed attacks. Treat exploitation as plausible, not confirmed in the wild. Authentication is indicated by the supplied CVSS vector, but the exact required privilege level is not documented.
Researcher notes
The evidence attributes injection to args.id within remove_rule and reports remote attack feasibility. Important unknowns include the exact authentication role, default endpoint exposure, exploit reliability, logging indicators, vendor acknowledgement, and fixed version. Validate these points through GL.iNet guidance before refining detection or remediation policy.
Mitigation direction
- Identify affected AX1800 devices and restrict their management interfaces to trusted networks immediately.
- Check GL.iNet guidance for patched firmware or vendor-approved remediation; no fixed version is identified in the sources.
- Block untrusted access to the RPC endpoint using network segmentation and management-plane controls.
- Monitor affected devices and upstream systems for unexpected administrative activity or system-command execution.
Validation and detection
- Inventory GL.iNet AX1800 devices and record their installed firmware versions.
- Flag devices running firmware 4.8.0 through 4.8.3 as affected.
- Confirm whether RPC and management interfaces are reachable from untrusted or lower-trust networks.
- Review available device and upstream logs for unexpected remove_rule activity or associated system behavior.
- After vendor remediation, verify the installed version and recheck management-plane reachability.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-74: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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.
Open ATT&CK lookupCWE-77: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. 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.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-18787 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9 (2.0)
- Known Exploited
- No
- Published
Vector: AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
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.
SSVC decision data
CVSS vector scores
4 official scoresWe 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.
AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR810VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R2.85.9VulDBCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R2.85.9VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P——VulDBVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
Base CVSS 2.0 score
9CriticalVector: AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- Source timelineVulDB
Advisory disclosed
- Source timelineVulDB
VulDB entry created
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Source timelineVulDB
VulDB entry last update
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- VDB-385788 | GL.iNet AX1800 RPC Endpoint oui-rpc.lua remove_rule command injectionCVE reference, VulDB · vdb-entry, technical-description
- VDB-385788 | CTI Indicators (IOB, IOC, TTP, IOA)CVE reference, VulDB · signature, permissions-required
- CVE-2026-18787 | CVE Analysis and ReportCVE reference, VulDB · third-party-advisory
- Submit #857346 | GL.iNet AX1800 4.8.3 Command InjectionCVE reference, VulDB · third-party-advisory
- https://github.com/xxianxiayubanmian/iot/blob/main/GL-link%20AX1800.mdCVE reference, VulDB · exploit
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Neutralization of Special Elements used in a Command ('Command Injection')
Improper Neutralization of Special Elements used in a Command ('Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.