Critical Memory corruption exploit reference

CVE-2026-7546 — Totolink NR1800X stack-based buffer overflow in find_host_ip (CVE-2026-7546)

A security vulnerability has been detected in Totolink NR1800X 9.1.0u.6279_B20210910. The impacted element is the function find_host_ip of the component lighttpd. Such manipulation of the argument Host leads to stack-based buffer overflow. The attack can be executed remotely. The exploit has been disclosed publicly and may be used.

Published May 1, 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 1% (30-day exploitation probability)+9
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

1.02%

ahead of 63% of scored CVEs · Oct 14, 2026

Affects

Totolink

NR1800X

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 NR1800X).
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 (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Totolink	NR1800X	version 9.1.0u.6279_B20210910	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-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 1.02%

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).
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Analysis and videos

CVE-2026-7546: Totolink NR1800X stack-based buffer overflow in find_host_ip
A stack-based buffer overflow has been reported in the find_host_ip function of the lighttpd component in Totolink NR1800X 9.1.0u.6279_B20210910, triggered by manipulation of the Host argument. According to the CNA record, the attack can be carried out remotely and a public exploit has been disclosed. The sources consulted show no confirmed exploitation in the wild, and the CVE is not listed in CISA KEV.

Timeline

What happened to this CVE, newest first.

2026
Affected products added · totolink/nr1800x
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
May 1, 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

vuldb.com/vuln/360357
vdb-entry, technical-description, NIST National Vulnerability Database
github.com/newym/cve/blob/main/totolinknr1800x.md
exploit, NIST National Vulnerability Database
vuldb.com/vuln/360357/cti
signature, permissions-required, NIST National Vulnerability Database
www.totolink.net/
product, NIST National Vulnerability Database
vuldb.com/submit/804404
third-party-advisory, NIST National Vulnerability Database

Elsewhere on this site

Totolink
every CVE for this vendor

Memory corruption
same class

CWE-119
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-7548 Totolink NR1800X cstecgi.cgi sub_41A68C command injection May 1, 2026
Critical CVE-2026-5030 Totolink NR1800X Telnet Service cstecgi.cgi NTPSyncWithHost command injection Mar 29, 2026
High CVE-2026-1328 Totolink NR1800X POST Request cstecgi.cgi setWizardCfg buffer overflow Jan 22, 2026
High CVE-2026-1326 Totolink NR1800X POST Request cstecgi.cgi setWanCfg command injection Jan 22, 2026
High CVE-2026-1327 Totolink NR1800X POST Request cstecgi.cgi setTracerouteCfg command injection Jan 22, 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-2026-7546 is "Totolink NR1800X stack-based buffer overflow in find_host_ip (CVE-2026-7546)", rated Critical. It affects NR1800X (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 1.02% 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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