7.1

CVE-2025-52952: Junos OS: MX Series with MPC-BUILTIN, MPC 1 through MPC 9: Receipt and processing of a malformed packet causes one or more FPCs to crash

Analyzed
Published 11-07-2025Last modified 11-07-2025

Vulnerability summary

CVE-2025-52952 is a high (CVSS 7.1) Out-of-bounds Write vulnerability in juniper networks junos os. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 23.9% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.1, adjacent network); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.1/10
010
High · v4.0 (CVE.org)
EPSS score
0.31%
0%100%
Low · +0.02 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 11-07-2025
    PublishedVulnerability first disclosed.
  2. 11-07-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.31%

Chance of exploitation in the next 30 days

Percentile

24%

Versus all other CVEs

30-day change

Increase +0.02 pp

From 0.29% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Juniper1 product
  • junos< 22.2 | 22.2 | 22.2:r1 | 22.2:r1-s1 | 22.2:r1-s2 | 22.2:r2 | 22.2:r2-s1 | 22.2:r2-s2 | 22.2:r3 | 22.4 | 22.4:r1 | 22.4:r1-s1 | 22.4:r1-s2
Juniper networks1 product
  • junos os< 22.2R3-S1 | ≥ 22.4, < 22.4R2

2 vendors · 2 products

References

2 links