AX1800: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2026-18787 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in AX1800 from GL.iNet, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected AX1800 versions: 4.8.0; 4.8.1; 4.8.2, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 3.21% chance of exploitation within 30 days, higher than 88% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of AX1800 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vuldb.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.4 | High | CNA (vuldb.com) |
| CVSS 3.1 | 8.8 | High | CNA (vuldb.com) |
| CVSS 2.0 | 9.0 | High | CNA (vuldb.com) |
Official description
A vulnerability was identified in GL.iNet AX1800 up to 4.8.3. The affected element is the function remove_rule of the file /usr/share/gl-ngx/oui-rpc.lua of the component RPC Endpoint. The manipulation of the argument args.id leads to command injection. The attack is possible to be carried out remotely. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in AX1800
- 8.3 High severity
- 7.4 High severity
- 7.4 High severity
- 8.3 High severity
- 7.5 High severity
- 7.8 High severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.3 High severity
- 9.8 Critical severity
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