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Fencer Vulns
medium 5.3

CVE-2024-39539 json

Junos OS: MX Series: Continuous subscriber logins will lead to a memory leak and eventually an FPC crash

published 2024-07-11 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-38065

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

A Missing Release of Memory after Effective Lifetime vulnerability in Juniper Networks Junos OS on MX Series allows an unauthenticated adjacent attacker to cause a Denial-of-Service (DoS).

In a subscriber management scenario continuous subscriber logins will trigger a memory leak and eventually lead to an FPC crash and restart.

This issue affects Junos OS on MX Series:

* All version before 21.2R3-S6, * 21.4 versions before 21.4R3-S6, * 22.1 versions before 22.1R3-S5, * 22.2 versions before 22.2R3-S3,  * 22.3 versions before 22.3R3-S2, * 22.4 versions before 22.4R3, * 23.2 versions before 23.2R2.

Patch / fix

  • Juniper Networks Junos OS 21.2R3-S6, 21.4R3-S6, 22.1R3-S5, 22.2R3-S3, 22.3R3-S2, 22.4R3, 23.2R2

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 6.0 CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
CNA 4.0 6.0 CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Juniper Networks Junos OS

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.