CVE-2026-109506 — Improper Authentication in Multiple TP-Link WiFi Repeaters
Multiple TP-Link Wi-Fi range extenders use a custom, reversible XOR-and-dictionary transformation in the HTTP web-management login flow. An unauthenticated attacker on the same local network who can capture the network traffic associated with legitimate administrator login may be able to derive an alternative credential value that produces the same accepted authentication result and use it to authenticate to the device’s web-management interface with administrator privileges. Exploitation requires the management login to use HTTP and the attacker to observe the session key, dictionary, and login value associated with a legitimate administrator login. Successful exploitation may allow an unauthenticated adjacent attacker to gain administrator access to the affected device and modify exposed configuration settings.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+4
- Technical severity (medium)+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.
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.
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 (TP-Link Systems Inc. RE190 v5, TP-Link Systems Inc. RE200 v5, TP-Link Systems Inc. RE205 v4…).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| TP-Link Systems Inc. | RE190 v5 | < V5_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE200 v5 | < V5_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE205 v4 | < V4_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE215 v1 | < V1_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE220 v3 | < V3_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE230 v2 | < V2_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE300 v2 | < V2_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE305 v4 | < V4_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE315 v1 | < V1_260904 rel3959 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE330 v1 | < V1_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE335 v1 | < V1_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE365 v2 | < V2_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE365 v3 | < V3_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE450 v4.8 | < V4_260915 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE550 v1 | < V1_260915 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| TP-Link Systems Inc. | RE750C v4 | < V4_260904 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
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 |
|---|---|---|---|---|---|
| 5.9 | CVSS 4.0 | Medium | — | — | f23511db-6c3e-4e32-a477-6aa17d310630 via NIST National Vulnerability Database |
| 5.9 | CVSS 4.0 | Medium | — | — | TPLink via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/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 (score shown at the top: f23511db-6c3e-4e32-a477-6aa17d310630) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
Timeline
What happened to this CVE, newest first.
- 2026
- SSVC assessment updated
- Source status changed · Received → Deferred
- Affected products added · tp-link systems inc./re190 v5, tp-link systems inc./re200 v5, tp-link systems inc./re205 v4, tp-link systems inc./re215
- Record published
- CVSS changed · 5.9
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
8 on the record
- www.tp-link.com/en/support/download/
- www.tp-link.com/us/support/download/
- nvd.nist.gov/vuln/detail/CVE-2026-109506
- github.com/advisories/GHSA-v8j9-72vh-g46g
- www.tp-link.com/us/support/download
- www.tp-link.com/us/support/faq/5344
- www.tp-link.com/en/support/download
- www.tp-link.com/us/support/faq/5344/
Elsewhere on this site
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-2026-109506 is "Improper Authentication in Multiple TP-Link WiFi Repeaters", rated Medium. It affects RE190 v5 (TP-Link Systems Inc.); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.9 describes technical severity. EPSS 0.35% 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.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.