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CVE Record

CVE-2026-76590: TRENDnet TEW-755AP ssi wan.cgi stack-based overflow

A vulnerability was identified in TRENDnet TEW-755AP up to 20260702. Affected by this issue is some unknown functionality of the file /cgi-bin/wan.cgi of the component ssi. Such manipulation of the argument cameo.wan.wan_pppoe_password_00 leads to stack-based buffer overflow. The attack can be executed remotely. The exploit is publicly available and might be used.

CriticalCVSS 9.9Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

CVE-2026-76590 is a remotely reachable memory-corruption flaw in the TRENDnet TEW-755AP. An authenticated, low-privilege attacker may be able to crash the device or compromise its confidentiality and integrity. Public proof-of-concept material increases near-term risk, but the supplied evidence does not establish active exploitation.

Executive priority

Treat as an urgent exposure-reduction issue. Identify affected access points immediately, remove management interfaces from untrusted reach, and seek vendor remediation. Prioritize internet-accessible or weakly segmented devices first. Public proof-of-concept availability raises urgency even though active exploitation is not established.

Technical view

The TEW-755AP firmware reported through build 20260702 contains a stack-based buffer overflow in the ssi functionality of /cgi-bin/wan.cgi. Manipulation of the cameo.wan.wan_pppoe_password_00 argument can trigger the flaw remotely. CVSS 3.1 rates it 9.9: network-accessible, low complexity, low privileges, no user interaction, changed scope, and high impact.

Likely exposure

Exposure is most likely where a TEW-755AP management interface is reachable from untrusted networks and low-privilege credentials can access the affected function. The bundle identifies firmware through build 20260702, but provides no complete version boundary, deployment prevalence, or authoritative fixed-release information.

Exploitation context

Public proof-of-concept code is referenced, demonstrating that technical details are available. However, the CVE is not listed as KEV in the supplied bundle, and no cited evidence confirms exploitation in the wild. Authentication is reportedly required, although only low privileges are needed.

Researcher notes

The record maps the flaw to CWE-119 and CWE-121. Important unknowns include the precise vulnerable version range, affected authentication roles, reliable compromise indicators, exploit reliability, and an official fixed build. Validate these through TRENDnet guidance before making fleet-wide patch assertions.

Mitigation direction

  • Inventory TEW-755AP devices and record their exact firmware builds.
  • Restrict management access to trusted administrative networks and authorized users.
  • Disable untrusted WAN access to the management interface where operationally feasible.
  • Review TRENDnet guidance for confirmed affected versions and an approved firmware update.
  • Replace or isolate devices if no supported remediation is available.

Validation and detection

  • Confirm device models and firmware builds using trusted inventory or management records.
  • Verify management interfaces are not publicly or broadly internally reachable.
  • Review account roles and remove unnecessary low-privilege management access.
  • Check device and network logs for unusual wan.cgi requests or unexplained restarts.
  • Confirm remediation against current TRENDnet guidance without running public exploit code.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · low confidence lookup

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 lookup
cwe · low confidence lookup

CWE-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 lookup
cve · low confidence lookup

CVE-2026-76590 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
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

Official CVE source material

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.

4CVSS vectors
6Timeline events
1ADP providers
7Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: noTechnical Impact: total

CVSS vector scores

4 official scores

We 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.

ScoreVersionSeverityVectorExploitImpactSource
9.9CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:R3.16VulDB
9.9CVSS 3.0CriticalCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:R3.16VulDB
9.4CVSS 4.0CriticalCVSS: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——VulDB
9CVSS 2.0CriticalAV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR810VulDB

Vulnerability scoring details

Base CVSS 4.0 score

9.4Critical
CVSS 4.0 vector shape for CVE-2026-76590Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: 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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. Source timelineVulDB

    Advisory disclosed

  2. Source timelineVulDB

    VulDB entry created

  3. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  4. Source timelineVulDB

    VulDB entry last update

  5. CVE publishedCVE Program

    The CVE record was published.

  6. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
TRENDnetTEW-755AP20260702Listed
Weakness

CWE details

CWE-119CWE-121

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.