Home

Description

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.

PUBLISHED Reserved 2025-09-23 | Published 2026-01-15 | Updated 2026-01-16 | Assigner juniper




HIGH: 7.4CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

MEDIUM: 6.3CVSS: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

Problem types

CWE-754 Improper Check for Unusual or Exceptional Conditions

Product status

Default status
unaffected

Any version before 21.2R3-S10
affected

21.4 (semver) before 21.4R3-S12
affected

22.2 (semver) before 22.2*
affected

22.4 (semver) before 22.4R3-S8
affected

23.2 (semver) before 23.2R2-S5
affected

23.4 (semver) before 23.4R2-S6
affected

24.2 (semver) before 24.2R2-S2
affected

24.4 (semver) before 24.4R2
affected

25.2 (semver) before 25.2R1-S1, 25.2R2
affected

Default status
unaffected

Any version before 21.4R3-S12-EVO
affected

22.2 (semver) before 22.2*
affected

22.4 (semver) before 22.4R3-S8-EVO
affected

23.2 (semver) before 23.2R2-S5-EVO
affected

23.4 (semver) before 23.4R2-S6-EVO
affected

24.2 (semver) before 24.2R2-S2-EVO
affected

24.4 (semver) before 24.4R2-EVO
affected

25.2 (semver) before 25.2R1-S1-EVO, 25.2R2-EVO
affected

Timeline

2026-01-14:Initial Publication

References

supportportal.juniper.net/ vendor-advisory

kb.juniper.net/JSA103149 vendor-advisory

cve.org (CVE-2025-59960)

nvd.nist.gov (CVE-2025-59960)

Download JSON