Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2026-33801

Severity CVSS v4.0:
HIGH
Type:
Unavailable / Other
Publication date:
09/07/2026
Last modified:
13/07/2026

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker sending a specific BGP update over an established BGP session to cause a Denial-of-Service (DoS).<br /> <br /> Upon receipt of a specifically malformed non-inet/inet6 unicast BGP update, an RPD crash and restart is triggered, which will cause a complete service outage until routing has reconverged. The rpd crash occurs before the update can be readvertised, so there is no downstream propagation.<br /> <br /> <br /> This issue affects:<br /> <br /> <br /> <br /> * Junos OS versions 25.2 before 25.2R2;<br /> <br /> <br /> * Junos OS Evolved versions 25.2 before 25.2R2-EVO.<br /> <br /> <br /> <br /> <br /> This issue doesn&amp;#39;t affect Junos OS versions before 25.2R1 nor Junos OS Evolved versions before 25.2R1-EVO.

Impact

Vector 4.0
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/AU:Y/R:A/RE:M CVSS v4.0 Severity and Metrics:

Base Score: 7.10 HIGH
Vector: 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/AU:Y/R:A/RE:M

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): None
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): Low
Automatable (AU): Yes
Recovery (R): Automatic
Vulnerability Response Effort (RE): Moderate

Base Score 4.0
7.10
Severity 4.0
HIGH
Vector 3.x
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 6.50 MEDIUM
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x
6.50
Severity 3.x
MEDIUM

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:juniper:junos:25.2:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:25.2:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:25.2:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:25.2:r1-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos_os_evolved:25.2:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos_os_evolved:25.2:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s2:*:*:*:*:*:*

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools