CVE-2025-52961 Denial of service in Junos OS Evolved
An unauthenticated adjacent attacker can cause a memory leak and FPC crash in Juniper PTX routers by sending specific valid traffic, resulting in denial of service.
- 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-2025-52961?
CVE-2025-52961 is a high-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 9 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An Uncontrolled Resource Consumption vulnerability in the Connectivity Fault Management (CFM) daemon and the Connectivity Fault Management Manager (cfmman) of Juniper Networks Junos OS Evolved on PTX10001-36MR, PTX10002-36QDD, PTX10004, PTX10008, PTX10016 allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).
An attacker on an adjacent device sending specific valid traffic can cause cfmd to spike the CPU to 100% and cfmman's memory to leak, eventually to cause the FPC crash and restart.
Continued receipt and processes of these specific valid packets will sustain the Denial of Service (DoS) condition.
An indicator of compromise is to watch for an increase in cfmman memory rising over time by issuing the following command and evaluating the RSS number. If the RSS is growing into GBs then consider restarting the device to temporarily clear memory. user@device> show system processes node fpc<num> detail | match cfmman
Example:
show system processes node fpc0 detail | match cfmman F S UID PID PPID PGID SID C PRI NI ADDR SZ WCHAN RSS PSR STIME TTY TIME CMD 4 S root 15204 1 15204 15204 0 80 0 - 90802 - 113652 4 Sep25 ? 00:15:28 /usr/bin/cfmman -p /var/pfe -o -c /usr/conf/cfmman-cfg-active.xml This issue affects Junos OS Evolved on PTX10001-36MR, PTX10002-36QDD, PTX10004, PTX10008, PTX10016:
* from 23.2R1-EVO before 23.2R2-S4-EVO, * from 23.4 before 23.4R2-S4-EVO, * from 24.2 before 24.2R2-EVO, * from 24.4 before 24.4R1-S2-EVO, 24.4R2-EVO.
This issue does not affect Junos OS Evolved on PTX10001-36MR, PTX10002-36QDD, PTX10004, PTX10008, PTX10016 before 23.2R1-EVO.
Weakness: CWE-400
Which versions are affected by CVE-2025-52961?
It affects 1 product.
Products include Juniper Junos Os Evolved.
How do I fix CVE-2025-52961?
No fix has been published for CVE-2025-52961 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-52961 being exploited?
There is no known exploitation of CVE-2025-52961 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos Os Evolved
- CVE-2026-21902 Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
- CVE-2023-28983 Junos OS Evolved: Shell Injection vulnerability in the gNOI server
- CVE-2025-21599 Denial of service in Junos OS Evolved
- CVE-2024-47502 Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS
- CVE-2024-39531 Junos OS Evolved: ACX 7000 Series: Protocol specific DDoS configuration affects other protocols
Sources
Also known as GHSA-6rrp-5qvj-5rj8.