Search/CVE-2025-21591
● CVE — High

CVE-2025-21591

VendorjuniperProductjunosDiscoveredApr 9, 2025UpdatedJan 26, 2026

A Buffer Access with Incorrect Length Value vulnerability in the jdhcpd daemon of Juniper Networks Junos OS, when DHCP snooping is enabled, allows an unauthenticated, adjacent, attacker to send a DHCP packet with a malformed DHCP option to cause jdhcp to crash creating a Denial of Service (DoS) condition. Continuous receipt of these DHCP packets using the malformed DHCP Option will create a sustained Denial of Service (DoS) condition. This issue affects Junos OS: * from 23.1 before 23.2R2-S3, * from 23.4 before 23.4R2-S3, * from 24.2 before 24.2R2. This issue isn't applicable to any versions of Junos OS before 23.1R1. This issue doesn't affect vSRX Series which doesn't support DHCP Snooping. This issue doesn't affect Junos OS Evolved. There are no indicators of compromise for this issue.

CVSS v3.1
7.4 HIGH
EPSS
0.34%
probability of exploitation in 30 days
CISA KEV
Not listed
no confirmed exploitation reported
News coverage
0
sources referencing this CVE
Related IOCs
0
seen in the same coverage
EPSS Trend
Aug 16, 2026 → Nov 3, 2026
▲ 0.02pp
0.32% → 0.34% over 3 tracked changes
CVSS v3.1 Detail
Attack VectorADJACENT
Attack ComplexityLOW
Privileges RequiredNONE
User InteractionNONE
ScopeCHANGED
ConfidentialityNONE
IntegrityNONE
AvailabilityHIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Connections
2 relationships
Timeline
disclosure → media coverage
Apr 9, 2025
Disclosure — published as a CVE record. · last revised by NVD Jan 26, 2026