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Fencer Vulns
high 7.4

CVE-2025-59960 json

Junos OS and Junos OS Evolved: DHCP Option 82 messages from clients being passed unmodified to the DHCP server

published 2026-01-15 9 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-2718

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Juniper DHCP service (jdhcpd) of Juniper Networks Junos OS and Junos OS Evolved allows a DHCP client in one subnet to exhaust the address pools of other subnets, leading to a Denial of Service (DoS) on the downstream DHCP server.

By default, the DHCP relay agent inserts its own Option 82 information when forwarding client requests, optionally replacing any Option 82 information provided by the client. When a specific DHCP DISCOVER is received in 'forward-only' mode with Option 82, the device should drop the message unless 'trust-option82' is configured. Instead, the DHCP relay forwards these packets to the DHCP server unmodified, which uses up addresses in the DHCP server's address pool, ultimately leading to address pool exhaustion.

This issue affects Junos OS:

* all versions before 21.2R3-S10, * from 21.4 before 21.4R3-S12, * all versions of 22.2, * from 22.4 before 22.4R3-S8,  * from 23.2 before 23.2R2-S5,  * from 23.4 before 23.4R2-S6,  * from 24.2 before 24.2R2-S2,  * from 24.4 before 24.4R2,  * from 25.2 before 25.2R1-S1, 25.2R2.

Junos OS Evolved:

* all versions before 21.4R3-S12-EVO,  * all versions of 22.2-EVO, * from 22.4 before 22.4R3-S8-EVO,  * from 23.2 before 23.2R2-S5-EVO,  * from 23.4 before 23.4R2-S6-EVO,  * from 24.2 before 24.2R2-S2-EVO,  * from 24.4 before 24.4R2-EVO,  * from 25.2 before 25.2R1-S1-EVO, 25.2R2-EVO.

Patch / fix

  • Juniper Networks Junos OS 21.2R3-S10, 21.4R3-S12, 22.4R3-S8, 23.2R2-S5, 23.4R2-S6, 24.2R2-S2, 24.4R2, 25.2R1-S1, 25.2R2
  • Juniper Networks Junos OS Evolved 21.4R3-S12-EVO, 22.4R3-S8-EVO, 23.2R2-S5-EVO, 23.4R2-S6-EVO, 24.2R2-S2-EVO, 24.4R2-EVO, 25.2R1-S1-EVO, 25.2R2-EVO

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
9 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA 4.0 6.3 CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:H/AU:Y/R:U/V:C/RE:M/U:Amber
CNA 4.0 6.3 CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:H/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:Y/R:U/V:C/RE:M/U:Amber

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved

Classification

Weakness
  • CWE-754 Improper Check for Unusual or Exceptional Conditions

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.