Comfast CF-N1-S mbox-config sprintf command injection

published 2026-08-20 2 mo ago modified 2026-10-18 21 d ago also EUVD-2026-63479

cvss: 7.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.8%; EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits: 0; none known

A flaw has been found in Comfast CF-N1-S 2.6.0.1. This impacts the function sprintf of the file /cgi-bin/mbox-config?method=SET&section=ptest_sn. Executing a manipulation of the argument sn can lead to command injection. The attack can be launched remotely. The exploit has been published and may be used.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-20)

Exploit prediction

1.77% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/lxiansheng488-bit/-/blob/main/%E5%8E%82%E5%95%86comefast%20%20CF-N1-S%20V2.pdf referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:P
CNA	3.1	7.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA	3.0	7.4	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:UR
CNA	4.0	2.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/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	7.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
CNA	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P

Affected products

Comfast CF-N1-S

Classification

Weakness

CWE-77 Improper Neutralization of Special Elements used in a Command
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component

References

github.com /lxiansheng488-bit/-/blob/main/%E5%8E%82%E5%95%86comefast%20%20CF-N1-S%20V2.pdf
exploit
vuldb.com /vuln/393623
vdb-entry, technical-description
vuldb.com /vuln/393623/cti
signature, permissions-required
vuldb.com /cve/CVE-2026-77004
third-party-advisory
vuldb.com /submit/880584
third-party-advisory

Sources

CVE List CVE-2026-77004
NVD CVE-2026-77004

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