Vulnerability in N/a

CVE-2026-36609

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.

Vulnerability class: POODLE (CVE-2014-3566)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (12.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-36609: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-36609?
CVE-2026-36609 is a high-severity vulnerability in N/a, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 7.3/10. Published 2026-06-03.
How severe is CVE-2026-36609?
High severity. CVSS v3 base score is 7.3 out of 10.