CVE Intelligence
High Memory corruption exploit reference

CVE-2026-4976 — Totolink LR350 cstecgi.cgi setWiFiGuestCfg buffer overflow

A vulnerability was found in Totolink LR350 9.3.5u.6369_B20220309. This vulnerability affects the function setWiFiGuestCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument ssid results in buffer overflow. The attack can be launched remotely. The exploit has been made public and could be used.

Published Mar 27, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulDB

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 (high)+6
  • CISA SSVC: exploitation "poc"+5

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
1.01%
ahead of 62% of scored CVEs · Oct 14, 2026
Affects
Totolink
LR350 and 1 more
CVSS base
8.8
High · 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
No
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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Totolink LR350, Totolink Lr350 Firmware).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. 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.

VendorProductVersionsStatusSource
Totolink LR350 version 9.3.5u.6369_B20220309 Vulnerable CVE Program (cve.org) e CISA ADP
Totolink Lr350 Firmware version 9.3.5u.6369_b20220309 Vulnerable NIST National Vulnerability Database

Attack characteristics

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

Attack vector
Network
Attack complexity
Low
Privileges required
Low
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.

ScoreVersionSeverityExpl.ImpactScored by
8.7 CVSS 4.0 High — — VulDB via CVE Program (cve.org) e CISA ADP
7.4 CVSS 4.0 High — — cna@vuldb.com via NIST National Vulnerability Database
8.8 CVSS 3.1 High 2.8 5.9 cna@vuldb.com via NIST National Vulnerability Database
8.8 CVSS 3.1 High — — VulDB via CVE Program (cve.org) e CISA ADP
8.8 CVSS 3.0 High — — VulDB via CVE Program (cve.org) e CISA ADP
9.0 CVSS 2.0 High 8.0 10.0 cna@vuldb.com via NIST National Vulnerability Database
9.0 CVSS 2.0 High — — VulDB via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:L/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 1.01%

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

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · totolink/lr350
    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 · 8.8
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Mar 27, 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

Elsewhere on this site

Totolink
every CVE for this vendor
CWE-119
other pages naming this weakness

Related CVEs (same products)

  • High CVE-2026-1158 Totolink LR350 POST Request cstecgi.cgi setWizardCfg buffer overflow Jan 19, 2026
  • High CVE-2026-1157 Totolink LR350 cstecgi.cgi setWiFiEasyCfg buffer overflow Jan 19, 2026
  • High CVE-2026-1156 Totolink LR350 cstecgi.cgi setWiFiBasicCfg buffer overflow Jan 19, 2026
  • High CVE-2026-1155 Totolink LR350 cstecgi.cgi setWiFiEasyGuestCfg buffer overflow Jan 19, 2026
  • High CVE-2026-1150 Totolink LR350 POST Request cstecgi.cgi setTracerouteCfg command injection Jan 19, 2026
  • High CVE-2026-1149 Totolink LR350 POST Request cstecgi.cgi setDiagnosisCfg command injection Jan 19, 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-2026-4976 is "Totolink LR350 cstecgi.cgi setWiFiGuestCfg buffer overflow", rated High. It affects LR350 (Totolink); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 1.01% 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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