CVE-2023-35086

HIGH

ASUS RT-AX56U V2 & RT-AC86U RCE via Format String in logmessage_normal

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2023-35086. PoCs published by tin-z.

AI-analyzed exploit summary This PoC demonstrates a format string vulnerability in ASUS router firmwares (RT-AX56U V2 and RT-AC86U) via the `detwan.cgi` endpoint, leading to DoS. The exploit crafts a malicious `action_mode` parameter to trigger the vulnerability in the `logmessage_normal` function.

Description

It is identified a format string vulnerability in ASUS RT-AX56U V2 & RT-AC86U. This vulnerability is caused by directly using input as a format string when calling syslog in logmessage_normal function, in the do_detwan_cgi module of httpd. A remote attacker with administrator privilege can exploit this vulnerability to perform remote arbitrary code execution, arbitrary system operation or disrupt service. This issue affects RT-AX56U V2: 3.0.0.4.386_50460; RT-AC86U: 3.0.0.4_386_51529.

Exploits (1)

nomisec WORKING POC 44 stars
by tin-z · poc
https://github.com/tin-z/CVE-2023-35086-POC

This PoC demonstrates a format string vulnerability in ASUS router firmwares (RT-AX56U V2 and RT-AC86U) via the `detwan.cgi` endpoint, leading to DoS. The exploit crafts a malicious `action_mode` parameter to trigger the vulnerability in the `logmessage_normal` function.

Classification
Working Poc 95%
Attack Type
Dos
Complexity
Trivial
Reliability
Reliable
Target: ASUS RT-AX56U V2 (≤3.0.0.4.386_50460), RT-AC86U (≤3.0.0.4_386_51529)
No auth needed
Prerequisites: Network access to the target router · HTTP service exposed on the target
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 7.2
EPSS 0.3971
EPSS Percentile 98.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-134
Status published
Products (2)
asus/rt-ac86u_firmware 3.0.0.4_386_51529
asus/rt-ax56u_v2_firmware 3.0.0.4.386_50460
Published Jul 21, 2023
Tracked Since Feb 18, 2026