CyberSecBulletin
CVE-2026-76784NVD status: Awaiting Analysis

HS103P3 / HS103P4 v5: Missing Cryptographic Step

Published Updated By the CyberSecBulletin desk

CVE-2026-76784 is a high-severity missing cryptographic step vulnerability in HS103P3 / HS103P4 v5 from TP-Link, with a CVSS 4.0 base score of 8.7 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists version 1.1.3 Build 250908 Rel.112508 as the first without the flaw, so updating HS103P3 / HS103P4 v5 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.2% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update HS103P3 / HS103P4 v5 to 1.1.3 Build 250908 Rel.112508 or a later version.
  2. Update EP10 to 1.1.1 Build 250908 Rel.112508 or a later version.
  3. Update EP25 V2 to 1.0.3 Build 240529 Rel.145252 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
TP-LinkHS103P3 / HS103P4 v5before 1.1.3 Build 250908 Rel.1125081.1.3 Build 250908 Rel.112508
TP-LinkEP10before 1.1.1 Build 250908 Rel.1125081.1.1 Build 250908 Rel.112508
TP-LinkEP25 V2before 1.0.3 Build 240529 Rel.1452521.0.3 Build 240529 Rel.145252
TP-LinkHS300 V2before 1.1.2 Build 241220 Rel.1713331.1.2 Build 241220 Rel.171333
TP-LinkKP303 V2before 1.1.2 Build 241220 Rel.1733211.1.2 Build 241220 Rel.173321
TP-LinkEP40Abefore 1.1.1 Build 250908 Rel.1125261.1.1 Build 250908 Rel.112526
TP-LinkKP125MP2 / KP125MP4before 1.2.5 Build 241213 Rel.1725041.2.5 Build 241213 Rel.172504
TP-LinkKP115before 1.1.1 Build 250908 Rel.1129451.1.1 Build 250908 Rel.112945
TP-LinkKS225before 1.1.1 Build 240626 Rel.1751251.1.1 Build 240626 Rel.175125
TP-LinkEP40Mbefore 1.1.0 Build 240415 Rel.1712191.1.0 Build 240415 Rel.171219
TP-LinkKS205before 1.1.1 Build 240724 Rel.1059201.1.1 Build 240724 Rel.105920
TP-LinkKS240before 1.0.6 Build 240122 Rel.1601001.0.6 Build 240122 Rel.160100
TP-LinkES20Mbefore 1.1.6 Build 250522 Rel.2102541.1.6 Build 250522 Rel.210254
TP-LinkKS220Mbefore 1.1.6 Build 250522 Rel.2102541.1.6 Build 250522 Rel.210254
TP-LinkKP200 V3before 1.1.0 Build 250225 Rel.1717241.1.0 Build 250225 Rel.171724
TP-LinkHS200 V5.26before 1.0.3 Build 240723 Rel.1926221.0.3 Build 240723 Rel.192622
TP-LinkHS220-LA(US) 6.6 / HS220-BL(US) 6.6before 1.0.3 Build 240723 Rel.1926301.0.3 Build 240723 Rel.192630
TP-LinkHS220 V3.26before 1.1.1 Build 240802 Rel.0941311.1.1 Build 240802 Rel.094131
TP-LinkHS220-LA(US) 4.6 / HS220-BL(US) 4.6before 1.1.1 Build 240802 Rel.0941421.1.1 Build 240802 Rel.094142
TP-LinkKL125before 1.1.1 Build 260710 Rel.0826461.1.1 Build 260710 Rel.082646

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/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. Scored by CNA.

Official description

Multiple TP-Link Kasa smart home devices contain insufficient cryptographic protections in the local device communication protocol. An adjacent network attacker may intercept, replay or forge locally exchanged control messages, potentially resulting in unauthorized device control. Successful exploitation could allow an attacker to manipulate the operational state of an affected device, resulting in unauthorized state changes, disruption of normal device functionality or a denial-of-service condition.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Cryptographic Step

The product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm.

More Missing Cryptographic Step vulnerabilities (CWE-325)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Missing Cryptographic Step vulnerabilities

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