Predictable Default Cryptographic Key Used for DES Encryption in TP-Link TL-WL841N
Summary
| CVE | CVE-2026-5039 |
|---|---|
| State | PUBLISHED |
| Assigner | TPLink |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-23 18:16:30 UTC |
| Updated | 2026-05-05 14:11:58 UTC |
| Description | TP-Link TL-WR841N v13 uses DES-CBC encryption in the TDDPv2 debug protocol with a cryptographic key derived from default web management credentials, making the key predictable if device is left in default configuration. A network-adjacent attacker can exploit this weakness to gain unauthorized access to the protocol, read debug data, modify certain device configuration values, and trigger device reboot, resulting in loss of integrity and a denial-of-service condition. |
Risk And Classification
Primary CVSS: v4.0 6.1 MEDIUM from f23511db-6c3e-4e32-a477-6aa17d310630
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/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
EPSS: 0.000150000 probability, percentile 0.032610000 (date 2026-05-05)
Problem Types: CWE-1394 | CWE-1394 CWE-1394 Use of default cryptographic key
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | f23511db-6c3e-4e32-a477-6aa17d310630 | Secondary | 6.1 | MEDIUM | CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 6.1 | MEDIUM | CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Primary | 8.8 | HIGH | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
AdjacentAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
LowIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/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
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Hardware | Tp-link | Tl-wr841n | 13.0 | All | All | All |
| Operating System | Tp-link | Tl-wr841n Firmware | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | TP-Link Systems Inc. | TL-WL841N V13 | affected 0.9.1 Build 20231120 Rel.62366 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.tp-link.com/us/support/download/tl-wr841n/v13 | f23511db-6c3e-4e32-a477-6aa17d310630 | www.tp-link.com | Product |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Ben Grinberg, Adiel Sol, Daniel Lubel, Erez Cohen, Nir Somech, Arad Inbar, Dream Group (en)
There are currently no legacy QID mappings associated with this CVE.