Critical Injection exploit reference

CVE-2026-5996 — Totolink A7100RU CGI Handler OS Command Injection (CVE-2026-5996)

A security vulnerability has been detected in Totolink A7100RU 7.4cu.2313_b20191024. The affected element is the function setAdvancedInfoShow of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. The manipulation of the argument tty_server leads to os command injection. It is possible to initiate the attack remotely. The exploit has been disclosed publicly and may be used.

Published Apr 9, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulDB

Moderate

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 3.3% (30-day exploitation probability)+13
Technical severity (critical)+10
CISA SSVC: exploitation "poc"+5
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

3.25%

ahead of 88% of scored CVEs · Oct 14, 2026

Affects

Totolink

A7100RU

CVSS base

9.8

Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Proof of concept

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Totolink A7100RU).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Totolink	A7100RU	version 7.4cu.2313_b20191024	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

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

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.3	CVSS 4.0	Critical	—	—	VulDB via CVE Program (cve.org) e CISA ADP
8.9	CVSS 4.0	High	—	—	cna@vuldb.com via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	3.9	5.9	cna@vuldb.com via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	—	—	VulDB via CVE Program (cve.org) e CISA ADP
9.8	CVSS 3.0	Critical	—	—	VulDB via CVE Program (cve.org) e CISA ADP
10.0	CVSS 2.0	High	10.0	10.0	cna@vuldb.com via NIST National Vulnerability Database
10.0	CVSS 2.0	High	—	—	VulDB via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: cna@vuldb.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-77 · Command Injection

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 3.25%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Look for parameters with command/query metacharacters and unexpected child processes of the service.

web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Analysis and videos

CVE-2026-5996: Totolink A7100RU CGI Handler OS Command Injection
A command injection flaw (CWE-77) was reported in the setAdvancedInfoShow function of the CGI Handler on Totolink A7100RU firmware 7.4cu.2313_b20191024, through the tty_server argument. The CNA VulDB rates it critical with CVSS 3.1 score 9.8 and describes remote attack potential. The record states the exploit was publicly disclosed, but the CVE is not listed in CISA KEV and no fixed version appears in the sources consulted.

Timeline

What happened to this CVE, newest first.

2026
Affected products added · totolink/a7100ru
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Deferred
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Apr 9, 2026 · VulDB

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

5 on the record

github.com/Litengzheng/vuldb_new/blob/main/A7100RU/vul_168/README.md
exploit, NIST National Vulnerability Database
www.totolink.net/
product, NIST National Vulnerability Database
vuldb.com/submit/792044
third-party-advisory, NIST National Vulnerability Database
vuldb.com/vuln/356550
vdb-entry, technical-description, NIST National Vulnerability Database
vuldb.com/vuln/356550/cti
signature, permissions-required, NIST National Vulnerability Database

Elsewhere on this site

Totolink
every CVE for this vendor

Injection
same class

CWE-77
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-6195 Totolink A7100RU command injection via admpass in setPasswordCfg Apr 13, 2026
Critical CVE-2026-6155 Totolink A7100RU OS Command Injection via setWanCfg pppoeServiceName Apr 13, 2026
Critical CVE-2026-6156 Totolink A7100RU OS Command Injection via setIpQosRules Apr 13, 2026
Critical CVE-2026-6154 Totolink A7100RU OS Command Injection in setWizardCfg (CVE-2026-6154) Apr 13, 2026
Critical CVE-2026-6140 Totolink A7100RU OS Command Injection via UploadFirmwareFile FileName Parameter Apr 12, 2026
Critical CVE-2026-6139 Totolink A7100RU OS Command Injection in UploadOpenVpnCert (CVE-2026-6139) Apr 12, 2026

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 fixed version, patch or mitigation documented.
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 record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-5996 is "Totolink A7100RU CGI Handler OS Command Injection (CVE-2026-5996)", rated Critical. It affects A7100RU (Totolink); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 3.25% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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