Junos Os EvolvedOperating system · Juniper

CVE-2025-52961

MEDIUM · 6.5 CVSS v3.1 Published 2025-10-09
No fix yet
No fix has been published. The vendor has not shipped a fixed release or patch. You remain exposed.
See remediation →
70/100
Remediation priority · Elevated
Public exploit No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-400

A single request can consume unbounded CPU, memory, or connections, so a modest amount of malicious traffic exhausts the service. The result is denial of service for everyone else. Remediation is enforcing limits, quotas, and timeouts on what any one request can use.

General guidance for the uncontrolled resource consumption class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Junos Os EvolvedOperating system
Affected:= 23.2= 23.4= 24.2= 24.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Recommended fix High confidence

Upgrade to 23.2R2-S4-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, or 24.4R1-S2-EVO/24.4R2-EVO depending on current branch

  1. 1. Identify the current Junos OS Evolved version running on the PTX device using `show version`
  2. 2. Based on the current version branch, plan upgrade to the minimum fixed release: For 23.2.x upgrade to 23.2R2-S4-EVO or later; For 23.4.x upgrade to 23.4R2-S4-EVO or later; For 24.2.x upgrade to 24.2R2-EVO or later; For 24.4.x upgrade to 24.4R1-S2-EVO or later, or 24.4R2-EVO
  3. 3. Download the appropriate Junos OS Evolved software image from the Juniper Networks support portal
  4. 4. Upload the software image to the device using `request system software add <path-to-package>`
  5. 5. Reboot the device to apply the new software version using `request system reboot`
  6. 6. After reboot, verify the new version is running with `show version`
  7. 7. Monitor the CFM daemon and cfmman process memory usage as described in the advisory to confirm the issue is resolved
Caveat Standard Junos OS upgrade procedures apply; ensure compatibility with existing network configuration and test in lab environment before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

No vendor fix exists Junos Os Evolved has not published a patch for this.

There is no version to upgrade to and no patch to apply. Every affected install stays exposed until the vendor ships a fix — or somebody else builds one.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-52961 in production — separate from our analysis above.

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