Security readout for executives and security teams
Plain-English summary
Tenda HG21 firmware V4.0.0-260302 reportedly contains hardcoded Admin credentials that can give an attacker root access. Because exploitation requires no prior privileges or user interaction and can occur over a network, compromise could expose device data, permit configuration changes, and disrupt service.
Executive priority
Treat this as an immediate asset-identification and exposure-reduction priority. Network-accessible affected devices could be fully compromised without user action. Restrict management access promptly and obtain vendor remediation guidance, while avoiding claims that exploitation is currently active.
Technical view
CVE-2026-38577 is classified as CWE-798, use of hardcoded credentials. The CVSS 3.1 score is 9.8 (critical), with network access, low complexity, no privileges, and no user interaction. Successful use of the Admin credentials reportedly provides root access, affecting confidentiality, integrity, and availability.
Likely exposure
Exposure is supported only for the Tenda HG21 running firmware V4.0.0-260302. Risk is greatest when an affected device's administrative service is reachable from untrusted networks. The structured affected-product fields are listed as unavailable, so broader model or version impact cannot be established from these sources.
Exploitation context
The CVSS vector indicates network-reachable, low-complexity exploitation without authentication or user interaction. However, the supplied record is not in KEV, and no cited source confirms active exploitation. Public disclosure may increase attacker awareness, but observed weaponization is not established.
Researcher notes
The record provides a specific model, firmware build, root-access outcome, CWE, and CVSS vector, but its structured affected fields contain only unavailable values. No vendor advisory, patch information, credential mechanics, or exploitation telemetry is supplied. Scope beyond HG21 V4.0.0-260302 remains unverified.
Mitigation direction
- Identify Tenda HG21 devices and confirm whether firmware V4.0.0-260302 is installed.
- Restrict administrative access to trusted management networks while awaiting authoritative vendor guidance.
- Prevent affected devices from being directly reachable from the public internet.
- Check Tenda guidance for an approved firmware update or credential remediation; none is named in the supplied sources.
- Isolate devices that cannot be adequately restricted or updated.
Validation and detection
- Verify each device's exact model and firmware using approved inventory or management interfaces.
- Confirm administrative services are inaccessible from public and other untrusted networks.
- Review authentication and configuration logs for unexplained Admin or root activity.
- Check whether device settings, accounts, or firmware changed without authorization.
- Reassess after applying any vendor-supported remediation.
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-798: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. 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 lookupCVE-2026-38577 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
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- 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
- https://gist.github.com/Anmolsingh142/a4be5a8c483f57e0887c1fc9e28b9e78CVE reference, mitre
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.
Use of Hard-coded Credentials
Use of Hard-coded Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.