CVE-2026-18686
CVE-2026-18686 — GL.iNet GL-MT3000 nas-web RPC Wrapper glc nas-web.add_user command injection
A vulnerability was detected in GL.iNet GL-MT3000 up to 4.4.5. The affected element is the function nas-web.add_user of the file /cgi-bin/glc of the component nas-web RPC Wrapper. Performing a manipulation results in command injection. The attack can be initiated remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure and confirmed the existence of the vulnerability.
Published Updated Sources: cvelistV5, VulDB
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
3%
chance of exploitation in 30 days
CVSS base
9.8
CRITICAL
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
PoC
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | CRITICAL | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-77
- CWE-74
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1562.003Impair Defenses: Impair Command History Logging
- T1574.006Hijack Execution Flow: Dynamic Linker Hijacking
- T1574.007Hijack Execution Flow: Path Interception by PATH Environment Variable
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /cgi-bin/glc.
References
5 on the record
- vuldb.com/vuln/385612
vdb-entry, technical-description
- vuldb.com/vuln/385612/cti
signature, permissions-required
- vuldb.com/cve/CVE-2026-18686
third-party-advisory
- vuldb.com/submit/856139
third-party-advisory
- github.com/coconut652-7/IOT_Vul_Public/tree/main/Glinet/MT3000/nas-web/ADD_USER_ADD_SHARE
exploit
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.