CVE-2026-36609 Weak cryptography in n/a
An attacker can recover plaintext passwords by exploiting static nonces and weak XOR encoding in Mercusys AC12G routers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-36609?
CVE-2026-36609 is a high-severity vulnerability in n/a, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-36609?
How do I fix CVE-2026-36609?
No fix has been published for CVE-2026-36609 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-36609 being exploited?
There is no known exploitation of CVE-2026-36609 in the wild and no public exploit code.
Sources
Also known as GHSA-wmgq-9q82-422r.