What is CVE-2026-74843?

CVE-2026-74843 is Wavlink WN531P3/WN535M1 Export Pingortrace CGI export_pingortrace.cgi strcpy stack-based overflow. The supplied enrichment data classifies it as Remote Code Exec mapped to CWE-121 CWE-121; CWE-119 CWE-119.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-74843. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-74843 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-74843. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS, EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-74843 using CVSS 10, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

criticalRemote Code Exec

CVE-2026-74843

CVE-2026-74843 — Wavlink WN531P3/WN535M1 Export Pingortrace CGI export_pingortrace.cgi strcpy stack-based overflow

A vulnerability was determined in Wavlink WN531P3 and WN535M1 V250922. Affected by this vulnerability is the function strcpy of the file /etc/lighttpd/www/cgi-bin/export_pingortrace.cgi of the component Export Pingortrace CGI. Executing a manipulation of the argument HTTP_COOKIE can lead to stack-based buffer overflow. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure.

Published Aug 17, 2026Updated Aug 17, 2026Sources: NVD, Wavlink (CNA), GitHub, SOCRadar CTI

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

ahead of 0% of scored CVEs

Affects

Wavlink

2 products listed

CVSS base

critical · 6 sources

Remediation

The vendor's own words where we have them.

Upgrade WN531P3 to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Wavlink	WN531P3	V250922	Vulnerable
Wavlink	WN535M1	V250922	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Changed

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

None

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
10	CVSS 3.1	critical	3.9	6	NVD
10	CVSS 2.0	high	10	10	vuldb.com (CNA)
10	CVSS 4.0	critical	—	—	Wavlink (CNA)
10	CVSS 3.1	critical	—	—	Wavlink (CNA)
10	CVSS 3.0	critical	—	—	Wavlink (CNA)
10	CVSS 2.0	critical	—	—	Wavlink (CNA)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer

Execute Unauthorized Code or Commands
Modify Memory
Read Memory
DoS: Crash, Exit, or Restart

Mitigation: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

CWE-121 · Stack-based Buffer Overflow

Modify Memory
DoS: Crash, Exit, or Restart
DoS: Resource Consumption (CPU)
DoS: Resource Consumption (Memory)

Mitigation: Run or compile the software using features or extensions that automatically provide a protection mechanism that mitigates or eliminates buffer overflows. For example, certain compilers and extensions provide automatic buffer overflow detection mechanisms that are built into the compiled code. Examples include the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice.

Weakness & attack patterns

CWE-121
CWE-119

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-10 · Buffer Overflow via Environment VariablesCAPEC-100 · Overflow BuffersCAPEC-123 · Buffer ManipulationCAPEC-14 · Client-side Injection-induced Buffer OverflowCAPEC-24 · Filter Failure through Buffer OverflowCAPEC-42 · MIME ConversionCAPEC-44 · Overflow Binary Resource FileCAPEC-45 · Buffer Overflow via Symbolic LinksCAPEC-46 · Overflow Variables and TagsCAPEC-47 · Buffer Overflow via Parameter ExpansionCAPEC-8 · Buffer Overflow in an API CallCAPEC-9 · Buffer Overflow in Local Command-Line Utilities

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 /etc/lighttpd/www/cgi-bin/export_pingortrace.cgi.
Prioritize edge telemetry for network-reachable WN531P3, WN535M1.

web/proxy/WAF logsapplication logsnetwork IDS/IPSEDR process telemetryhost service logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 10.0 (AV:N)
Aug 17, 2026 · NVD
Initial · CVE published
Aug 17, 2026 · NVD
Reported · Advisory disclosed
Aug 17, 2026 · Wavlink
Reported · VulDB entry created
Aug 17, 2026 · Wavlink
Reported · VulDB entry last update
Aug 17, 2026 · Wavlink

Source activity

Readings a source repeats on a schedule, counted rather than listed.

2×ModifiedAug 17, 2026 · SOCRadar CTI
1×Tweets · 1 time tweeted.Aug 17, 2026 · SOCRadar CTI
1×SVRS is calculatedAug 17, 2026 · SOCRadar CTI

References

5 on the record

github.com/wcndsb-sketch/WAVLINK_WN535M1-M35M1_V250922-Buffer-Overflow/blob/main/CVE-Report-WAVLINK-WN535M1-RCE.pdf
Exploit, Third Party Advisory, NIST
vuldb.com/cve/CVE-2026-74843
Vendor Advisory
vuldb.com/submit/875331
Vendor Advisory
vuldb.com/vuln/391205
Vendor Advisory
vuldb.com/vuln/391205/cti
Vendor Advisory

Elsewhere on this site

Wavlinkevery CVE for this vendor
Remote Code Execsame class
CWE-121other pages naming this weakness

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.

Answered from this record1

What should defenders know first?

CVE-2026-74843 is Wavlink WN531P3/WN535M1 Export Pingortrace CGI export_pingortrace.cgi strcpy stack-based overflow, a critical vulnerability affecting WN531P3, WN535M1 from Wavlink. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-74843. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-74843. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 10 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.