Wavlink WL-WN579X3-C UPNP firewall.cgi sub_4019FC stack-based overflow

published 2026-03-28 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-16937

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits: 0; none known

A vulnerability was determined in Wavlink WL-WN579X3-C 231124. This impacts the function sub_4019FC of the file /cgi-bin/firewall.cgi of the component UPNP Handler. Executing a manipulation of the argument UpnpEnabled can lead to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 7 mo ago (2026-03-30)

Exploit prediction

0.70% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/Litengzheng/vul_db/blob/main/WL-WN579X3-C/vul_200/README.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.7	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
CNA	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
CNA	3.0	8.8	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
CNA	2.0	9.0	AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
CNA	4.0	7.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA	2.0	9.0	AV:N/AC:L/Au:S/C:C/I:C/A:C

Affected products

Wavlink WL-WN579X3-C

Classification

Weakness

CWE-121 Stack-based Buffer Overflow
CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-787 Out-of-bounds Write

References

github.com /Litengzheng/vul_db/blob/main/WL-WN579X3-C/vul_200/README.md
exploit, third-party-advisory
vuldb.com /vuln/353891
vdb-entry, technical-description, third-party-advisory
vuldb.com /vuln/353891/cti
signature, permissions-required, vdb-entry
vuldb.com /submit/779149
third-party-advisory, vdb-entry

Sources

CVE List CVE-2026-5004
NVD CVE-2026-5004

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary