Archer AX55 v4: Stack-based Buffer Overflow
CVE-2026-18167 is a high-severity stack-based buffer overflow vulnerability in Archer AX55 v4 from TP-Link, with a CVSS 4.0 base score of 7.7 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 1.2.1 Build 20260527 as the first without the flaw, so updating Archer AX55 v4 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Archer AX55 v4 to 1.2.1 Build 20260527 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| TP-Link | Archer AX55 v4 | before 1.2.1 Build 20260527 | 1.2.1 Build 20260527 |
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
- HighSuccess depends on conditions outside the attacker's control.
- Attack requirements
- PresentThe target must be in a specific state or configuration for the attack to work.
- 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)
- LowLimited loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- LowLimited loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- LowLimited loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/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
A stack-based buffer overflow vulnerability exists in the EasyMesh module of TP-Link Archer AX55 v4. When Mesh mode is enabled, a LAN attacker may submit crafted input that causes the easymesh daemon to crash and may potentially achieve remote code execution on the device. Successful exploitation may cause the EasyMesh daemon to crash and may potentially allow remote code execution when Mesh mode is enabled. This may result in high impact to the confidentiality, integrity, and availability of the affected device.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Stack-based Buffer Overflow vulnerabilities
- 7.8 High severity
- 7.4 High severity
- 8.3 High severity
- 9.8 Critical severity
- 7.1 High severity
- 8.8 High severity
Spotted an error? Tell us.