CVE-2025-59960: Juniper Networks Junos OS · Unchecked Error Condition
Affects Juniper Networks Junos OSSource CVE Database V5
Not known to be exploited · CVSS 7.4 High · fixed in 25.2R1-S1 : patch Juniper Networks Junos OS soon.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 25.2R1-S1, 24.4R2, 24.2R2-S2 +12
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Juniper NetworksJunos OS | Affected
| Fixed in
|
| Juniper NetworksJunos OS Evolved | Affected
| Fixed in
|
AI-suggested
European organizations should immediately assess their Juniper device inventory to identify affected Junos OS and Junos OS Evolved versions. Applying the vendor-provided patches and updates to fixed versions (e.g., 21.2R3-S10 or later) is the most effective mitigation. If you cannot patch yet, network administrators should consider disabling DHCP relay agents where not necessary or restricting DHCP relay functionality to trusted network segments. Configuring the DHCP relay agent to enable 'trust-option82' only when appropriate and ensuring strict validation of DHCP packets can reduce risk. Implementing network segmentation and access control lists (ACLs) to limit DHCP traffic from untrusted subnets can prevent malicious clients from exploiting this vulnerability. Monitoring DHCP server logs for unusual address allocation patterns and setting alerts for rapid address pool depletion can provide early detection. Additionally, organizations should review their incident response plans to handle potential DHCP service disruptions. Coordination with Juniper support for guidance and updates is recommended.
Description
CVE-2025-59960 is a high-severity vulnerability in Juniper Networks Junos OS and Junos OS Evolved affecting the DHCP relay agent. The flaw allows a DHCP client in one subnet to exhaust DHCP address pools of other subnets by exploiting improper handling of DHCP Option 82 in 'forward-only' mode. This leads to denial of service (DoS) on downstream DHCP servers by depleting available IP addresses. The vulnerability affects multiple Junos OS versions prior to various fixed releases starting from 21.2R3-S10 and corresponding Junos OS Evolved versions. Exploitation requires network access but no authentication or user interaction, with a CVSS score of 7.4. No known exploits are currently reported in the wild. European organizations using vulnerable Juniper devices should prioritize patching and consider network segmentation and DHCP relay configuration hardening to mitigate risk.