CVE-2025-52952 Memory corruption in Junos OS

High 7.1 Published 11 Jul 2025 Updated 11 Jul 2025

An unauthenticated adjacent attacker can cause a sustained Denial of Service on Juniper MX routers by sending malformed packets to the CFM daemon.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-52952?

CVE-2025-52952 is a high-severity memory corruption vulnerability in Juniper Junos, published on 11 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper Networks Junos OS on MX Series with MPC-BUILTIN, MPC1 through MPC9 line cards allows an unauthenticated adjacent attacker to send a malformed packet to the device, leading to an FPC crash and restart, resulting in a Denial of Service (DoS).

Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.

This issue affects Juniper Networks: Junos OS: * All versions before 22.2R3-S1, * from 22.4 before 22.4R2.

This feature is not enabled by default.

Weakness: CWE-787

Which versions are affected by CVE-2025-52952?

It affects 1 product.

Products include Juniper Junos.

How do I fix CVE-2025-52952?

No fix has been published for CVE-2025-52952 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-52952 being exploited?

There is no known exploitation of CVE-2025-52952 in the wild and no public exploit code.

All Juniper Junos vulnerabilities

Sources

Also known as GHSA-pwqr-fp7x-9xcp.