Security readout for executives and security teams
Plain-English summary
Tenda CP3 firmware 27.5.57.101 contains an access-control flaw in redirect configuration. A remote attacker who already has high privileges may improperly change this setting, potentially compromising the device and connected operations. The supplied sources do not establish exploitation in the wild or identify a vendor patch.
Executive priority
Prioritize immediate discovery and access restriction, especially where CP3 management is exposed beyond trusted networks. Schedule vendor remediation promptly when confirmed. The high impact warrants urgent attention, while the high-privilege prerequisite and absence of confirmed exploitation reduce the case for emergency shutdown based solely on supplied evidence.
Technical view
The flaw affects CRedirServer::SetRedirectEnable in Functions/Redirect.cpp and is classified as improper privilege management (CWE-266/CWE-269). CVSS 4.0 rates it 9.4: network-reachable, low complexity, no user interaction, but requiring high privileges, with potentially high confidentiality, integrity, and availability impacts.
Likely exposure
Confirmed scope is limited to Tenda CP3 firmware 27.5.57.101. Exposure depends on whether affected devices are deployed and whether their management functionality is remotely reachable. The supplied evidence does not establish other affected versions, configurations, or products.
Exploitation context
Remote exploitation is described as possible, but the CVSS vector indicates an attacker must already hold high privileges. KEV is false, and no supplied source confirms active exploitation, public exploit availability, or observed attacks. Treat the flaw as serious without assuming it is currently weaponized.
Researcher notes
Public detail is limited to the affected function, file, weakness classification, version, and remote attack characterization. The supplied material does not explain the authorization boundary, vulnerable request path, authentication assumptions, affected default configuration, indicators, patch, or reliable detection method. Additional vendor or primary technical analysis is needed.
Mitigation direction
- Inventory Tenda CP3 devices and identify those running firmware 27.5.57.101.
- Restrict device management access to trusted administrators and controlled networks.
- Review privileged accounts and revoke unnecessary, stale, or compromised access.
- Check Tenda guidance for patched firmware or an approved mitigation.
- Apply vendor-provided remediation when available and verify the installed version.
Validation and detection
- Confirm each CP3 device model and exact installed firmware version.
- Test whether management interfaces are reachable from untrusted networks.
- Review administrator accounts, roles, and recent privileged access.
- Inspect available management logs for unexpected redirect-setting changes.
- Verify Tenda's current advisory and firmware status before closing 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-266: 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-269: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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-2026-86153 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
- 9.4 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X——VulDBCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:X/RL:X/RC:R2.36VulDBCVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:X/RL:X/RC:R2.36VulDBAV:N/AC:L/Au:M/C:C/I:C/A:C/E:ND/RL:ND/RC:UR6.410VulDBVulnerability scoring details
Base CVSS 4.0 score
9.4CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:X/RL:X/RC:R
Base CVSS 3.0 score
9.1CriticalVector: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:X/RL:X/RC:R
Base CVSS 2.0 score
8.3HighVector: AV:N/AC:L/Au:M/C:C/I:C/A:C/E:ND/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-399276 | Tenda CP3 Redirect.cpp SetRedirectEnable privileges managementCVE reference, VulDB · vdb-entry, technical-description
- VDB-399276 | CTI Indicators (IOB, IOC, TTP, IOA)CVE reference, VulDB · signature, permissions-required
- CVE-2026-86153 | CVE Analysis and ReportCVE reference, VulDB · third-party-advisory
- Submit #895354 | Tenda CP3 V3.2 V27.5.57.101 Improper Access ControlsCVE reference, VulDB · third-party-advisory
- https://www.tenda.com.cn/CVE reference, VulDB · product
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.
Incorrect Privilege Assignment
Incorrect Privilege Assignment represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Privilege Management
Improper Privilege Management represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.