SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-36609

Combined with the predictable XOR-based password encoding (securityEncode function), this allows an attacker to reverse captured authentication tokens to recover the plaintext password.

HIGH 7.3EPSS 0.17%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 uses a static authentication nonce that does not change between requests from the same source IP. Combined with the predictable XOR-based password encoding (securityEncode function), this allows an attacker to reverse captured authentication tokens to recover the plaintext password.

CVSS 3.1
7.3 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS
0.17% probability · 6th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-327, CWE-341
Source
cve@mitre.org
EPSS trend
0%3%5%27 October 2026: 0.17%27 October 202627 October 2026

EPSS 0.2% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.