CVE-2025-21595 | Junos OS and Junos OS Evolved: In an EVPN-VXLAN scenario specific ARP or NDP packets cause FPC to crash

A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause an FPC to crash, leading to Denial of Service (DoS). On all Junos OS and Junos OS Evolved platforms, in an EVPN-VXLAN scenario, when specific ARP packets are received on an IPv4 network, or specific NDP packets are received on an IPv6 network, kernel heap memory leaks, which eventually leads to an FPC crash and restart. This issue does not affect MX Series platforms. Heap size growth on FPC can be seen using below command. user@host> show chassis fpc                     Temp CPU Utilization (%) CPU Utilization (%) Memory   Utilization (%) Slot State           (C) Total Interrupt     1min   5min   15min   DRAM (MB)   Heap   Buffer   0 Online           45     3         0       2       2      2       32768      19       0 <<<<<<< Heap increase in all fPCs This issue affects Junos OS: * All versions before 21.2R3-S7, * 21.4 versions before 21.4R3-S4, * 22.2 versions before 22.2R3-S1,  * 22.3 versions before 22.3R3-S1,  * 22.4 versions before 22.4R2-S2, 22.4R3. and Junos OS Evolved: * All versions before 21.2R3-S7-EVO, * 21.4-EVO versions before 21.4R3-S4-EVO, * 22.2-EVO versions before 22.2R3-S1-EVO,  * 22.3-EVO versions before 22.3R3-S1-EVO,  * 22.4-EVO versions before 22.4R3-EVO.

Published: 2025-04-09 Last update: 2026-01-26 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-21595 is rated Moderate Risk (40/100): CVSS High severity, with low exploitation likelihood (EPSS 0.14%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-21595

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-24 0.18% 0.14% -0.04%
2 2026-05-23 0.07% 0.18% +0.10%
3 2026-02-03 — 0.07% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21595

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 4.0 HIGH
CVSS:4.0/AV:A/AC:L/AT:N/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 Click to expand
Attack vector (AV:A)
Attacker has to be on an adjacent/local network segment.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:L)
Limited availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]

Weakness enumeration for CVE-2025-21595

Affected software / configurations for CVE-2025-21595

Vendor Product Version Raw CPE
juniper junos < 21.2 cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:-:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r1:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r1-s1:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r1-s2:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r2:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r2-s1:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r2-s2:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r3:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r3-s1:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r3-s2:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r3-s3:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r3-s4:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r3-s5:*:*:*:*:*:*
juniper junos 21.2 cpe:2.3:o:juniper:junos:21.2:r3-s6:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:-:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r1:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r1-s1:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r1-s2:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r2:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r2-s1:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r2-s2:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r3:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r3-s1:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r3-s2:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r3-s3:*:*:*:*:*:*
juniper junos 21.4 cpe:2.3:o:juniper:junos:21.4:r3-s4:*:*:*:*:*:*
juniper junos 22.2 cpe:2.3:o:juniper:junos:22.2:-:*:*:*:*:*:*
juniper junos 22.2 cpe:2.3:o:juniper:junos:22.2:r1:*:*:*:*:*:*
juniper junos 22.2 cpe:2.3:o:juniper:junos:22.2:r1-s1:*:*:*:*:*:*
juniper junos 22.2 cpe:2.3:o:juniper:junos:22.2:r1-s2:*:*:*:*:*:*
juniper junos 22.2 cpe:2.3:o:juniper:junos:22.2:r2:*:*:*:*:*:*
juniper junos 22.2 cpe:2.3:o:juniper:junos:22.2:r2-s1:*:*:*:*:*:*
juniper junos 22.2 cpe:2.3:o:juniper:junos:22.2:r2-s2:*:*:*:*:*:*
juniper junos 22.2 cpe:2.3:o:juniper:junos:22.2:r3:*:*:*:*:*:*
juniper junos 22.3 cpe:2.3:o:juniper:junos:22.3:-:*:*:*:*:*:*
juniper junos 22.3 cpe:2.3:o:juniper:junos:22.3:r1:*:*:*:*:*:*
juniper junos 22.3 cpe:2.3:o:juniper:junos:22.3:r1-s1:*:*:*:*:*:*
juniper junos 22.3 cpe:2.3:o:juniper:junos:22.3:r1-s2:*:*:*:*:*:*
juniper junos 22.3 cpe:2.3:o:juniper:junos:22.3:r2:*:*:*:*:*:*
juniper junos 22.3 cpe:2.3:o:juniper:junos:22.3:r2-s1:*:*:*:*:*:*
juniper junos 22.3 cpe:2.3:o:juniper:junos:22.3:r2-s2:*:*:*:*:*:*
juniper junos 22.3 cpe:2.3:o:juniper:junos:22.3:r3:*:*:*:*:*:*
juniper junos 22.4 cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:*
juniper junos 22.4 cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:*
juniper junos 22.4 cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:*
juniper junos 22.4 cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:*
juniper junos 22.4 cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:*
juniper junos 22.4 cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:*
juniper junos 22.4 cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:*
juniper junos_os_evolved < 21.2 cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:-:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r1:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r1-s1:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r1-s2:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r2:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r2-s1:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r2-s2:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r3:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r3-s1:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r3-s2:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r3-s3:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r3-s4:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r3-s5:*:*:*:*:*:*
juniper junos_os_evolved 21.2 cpe:2.3:o:juniper:junos_os_evolved:21.2:r3-s6:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:-:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r1:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r1-s1:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r1-s2:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r2:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r2-s1:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r2-s2:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r3:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r3-s1:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r3-s2:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r3-s3:*:*:*:*:*:*
juniper junos_os_evolved 21.4 cpe:2.3:o:juniper:junos_os_evolved:21.4:r3-s4:*:*:*:*:*:*
juniper junos_os_evolved 22.2 cpe:2.3:o:juniper:junos_os_evolved:22.2:-:*:*:*:*:*:*
juniper junos_os_evolved 22.2 cpe:2.3:o:juniper:junos_os_evolved:22.2:r1:*:*:*:*:*:*
juniper junos_os_evolved 22.2 cpe:2.3:o:juniper:junos_os_evolved:22.2:r1-s1:*:*:*:*:*:*

References for CVE-2025-21595

cvelogic Threat Intelligence