CVE-2025-21595

FPC crash via unreleased packet-processing memory

Published Apr 9, 2025 · Updated Apr 10, 2025

Memory exhaustion in the PFE of Junos OS and Junos OS Evolved allows attackers to crash and restart an FPC with crafted packets. In an EVPN-VXLAN configuration, processing specific IPv4 ARP or IPv6 NDP packets fails to release kernel heap memory, so repeated packets exhaust the heap. The sender must be adjacent to the target network, and the bounded consequence is packet-forwarding interruption during the FPC restart; MX Series platforms are unaffected.

CVSS severity7.1
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory exhaustion in the PFE of Junos OS and Junos OS Evolved allows attackers to crash and restart an FPC with crafted packets. In an EVPN-VXLAN configuration, processing specific IPv4 ARP or IPv6 NDP packets fails to release kernel heap memory, so repeated packets exhaust the heap. The sender must be adjacent to the target network, and the bounded consequence is packet-forwarding interruption during the FPC restart; MX Series platforms are unaffected.

The record

CVE
CVE-2025-21595
Published
Apr 9, 2025
Updated
Apr 10, 2025
Vendor
Juniper Networks
Product
Junos OS Evolved
Classifications
CWE-401, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <21.2R3-S7-EVO
  2. Affected versionversion=21.4-EVO <21.4R3-S4-EVO
  3. Affected versionversion=22.2-EVO <22.2R3-S1-EVO
  4. Affected versionversion=22.3-EVO <22.3R3-S1-EVO
  5. Affected versionversion=22.4-EVO <22.4R3-EVO

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OS Evolvedversion=0 <21.2R3-S7-EVO; version=21.4-EVO <21.4R3-S4-EVO; version=22.2-EVO <22.2R3-S1-EVO; version=22.3-EVO <22.3R3-S1-EVO; version=22.4-EVO <22.4R3-EVO
Juniper Networks · Junos OSversion=0 <21.2R3-S7; version=21.4 <21.4R3-S4; version=22.2 <22.2R3-S1; version=22.3 <22.3R3-S1; version=22.4 <22.4R2-S2, 22.4R3

Published CVSS scores

7.1Juniper NetworksCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
6.5Juniper NetworksCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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