Security readout for executives and security teams
Plain-English summary
A remotely reachable, authenticated attacker with low privileges may be able to crash or take control of an affected TRENDnet router by submitting an oversized WAN L2TP password. The reported impact includes loss of confidentiality, integrity, and availability. Evidence is limited to TEW-823DRU firmware 1.1.02b01.
Executive priority
Treat confirmed TEW-823DRU 1.1.02b01 deployments as an urgent remediation item, especially when management access crosses untrusted networks. Public proof-of-concept availability and potential device takeover justify rapid isolation and vendor-guidance review. Do not describe this as active exploitation without new evidence.
Technical view
CVE-2026-75976 is a stack-based buffer overflow in /cgi-bin/wan.cgi. Unsafe strcpy handling of the NVRAM wan_l2tp_password argument can overwrite stack memory. The CVSS 3.1 vector indicates network access, low complexity, low privileges, no user interaction, changed scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where TEW-823DRU administration interfaces running firmware 1.1.02b01 are reachable by untrusted or compromised networks. Authentication is reportedly required, reducing unauthenticated exposure but leaving risk from stolen credentials, low-privilege accounts, or internal attackers. Other models and versions are not established as affected.
Exploitation context
A public proof of concept is referenced, so attackers can study and potentially adapt existing research. However, the bundle states that this CVE is not in KEV and provides no evidence of active exploitation. Public exploit availability should therefore be treated as elevated potential risk, not confirmation of attacks in the wild.
Researcher notes
The report maps to CWE-119 and CWE-121 and identifies the vulnerable sink, CGI path, component, and parameter. The supplied material does not establish exact buffer size, reliable code execution, affected versions beyond 1.1.02b01, vendor patch availability, or exploitation in the wild. Validate those points through vendor documentation before broadening conclusions.
Mitigation direction
- Identify and prioritize every TEW-823DRU device running firmware 1.1.02b01.
- Restrict management access to trusted administrative networks and authorized accounts.
- Disable remote administration from untrusted networks where operationally feasible.
- Check TRENDnet guidance for patched firmware or an approved mitigation; none is identified in the supplied sources.
- Replace or isolate affected devices if no supported remediation is available.
Validation and detection
- Inventory device models and record exact installed firmware versions.
- Confirm management interfaces are not exposed to the public internet or untrusted networks.
- Review administrative accounts for unnecessary low-privilege access and signs of credential compromise.
- Monitor affected devices for unexpected restarts, configuration changes, or administrative access.
- Verify remediation against current TRENDnet guidance without using the public proof of concept in production.
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-119: 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-121: 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 lookupCVE-2026-75976 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
- 9.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:R
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:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:R3.16VulDBCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:R3.16VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P——VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR810VulDBVulnerability scoring details
Base CVSS 4.0 score
9.4CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P
Base CVSS 3.1 score
9.9CriticalVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:R
Base CVSS 3.0 score
9.9CriticalVector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/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-391892 | TRENDnet TEW-823DRU NVRAM wan.cgi strcpy stack-based overflowCVE reference, VulDB · vdb-entry, technical-description
- VDB-391892 | CTI Indicators (IOB, IOC, IOA)CVE reference, VulDB · signature, permissions-required
- CVE-2026-75976 | CVE Analysis and ReportCVE reference, VulDB · third-party-advisory
- Submit #877796 | TRENDnet TEW-823DRU TEW-823DRU Stack-based Buffer OverflowCVE reference, VulDB · third-party-advisory
- https://github.com/meishigana/CVE/tree/main/team15_20260702/10_823dru-rc-bofCVE reference, VulDB · related
- https://github.com/meishigana/CVE/blob/main/team15_20260702/10_823dru-rc-bof/poc/poc-rc-overflow.pyCVE 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 Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.