CVE-2026-33801: CWE-754 Improper Check for Unusual or Exceptional Conditions in Juniper Networks Junos OS
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). 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. This issue affects: * Junos OS versions 25.2 before 25.2R2; * Junos OS Evolved versions 25.2 before 25.2R2-EVO. This issue doesn't affect Junos OS versions before 25.2R1 nor Junos OS Evolved versions before 25.2R1-EVO.
AI Analysis
Technical Summary
An improper check for unusual or exceptional conditions in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a denial-of-service by sending a malformed non-inet/inet6 unicast BGP update over an established BGP session. This triggers an RPD crash and restart, resulting in service outage until routing reconverges. The vulnerability affects Junos OS and Junos OS Evolved versions 25.2 before 25.2R2 and 25.2R2-EVO respectively, but not versions before 25.2R1 or 25.2R1-EVO.
Potential Impact
Successful exploitation causes the routing protocol daemon (RPD) to crash and restart, leading to a denial-of-service condition and complete service outage until routing reconverges. There is no impact on confidentiality or integrity, and no downstream propagation of the malformed update occurs.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is documented in the provided data. Until a patch is available, consider limiting adjacency to trusted peers and monitoring BGP sessions for unusual updates.
CVE-2026-33801: CWE-754 Improper Check for Unusual or Exceptional Conditions in Juniper Networks Junos OS
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). 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. This issue affects: * Junos OS versions 25.2 before 25.2R2; * Junos OS Evolved versions 25.2 before 25.2R2-EVO. This issue doesn't affect Junos OS versions before 25.2R1 nor Junos OS Evolved versions before 25.2R1-EVO.
CVSS v3.1
Score 6.5medium
Affected software
pkg:github/juniper-networks/junos-ospkg:github/juniper-networks/junos-os-evolvedRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
An improper check for unusual or exceptional conditions in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a denial-of-service by sending a malformed non-inet/inet6 unicast BGP update over an established BGP session. This triggers an RPD crash and restart, resulting in service outage until routing reconverges. The vulnerability affects Junos OS and Junos OS Evolved versions 25.2 before 25.2R2 and 25.2R2-EVO respectively, but not versions before 25.2R1 or 25.2R1-EVO.
Potential Impact
Successful exploitation causes the routing protocol daemon (RPD) to crash and restart, leading to a denial-of-service condition and complete service outage until routing reconverges. There is no impact on confidentiality or integrity, and no downstream propagation of the malformed update occurs.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is documented in the provided data. Until a patch is available, consider limiting adjacency to trusted peers and monitoring BGP sessions for unusual updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- juniper
- Date Reserved
- 2026-03-23T19:46:13.673Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a50101d68715ace43153c5e
Added to database: 07/09/2026, 21:18:21 UTC
Last enriched: 07/17/2026, 09:57:47 UTC
Last updated: 08/23/2026, 22:52:10 UTC
Views: 82
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