CVE-2026-33801

CVE-2026-33801 is a medium-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-754.

Key facts

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.

Frequently asked questions

What is CVE-2026-33801?
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.
How severe is CVE-2026-33801?
CVE-2026-33801 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-33801 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33801?
CVE-2026-33801 primarily affects Juniper Junos. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-33801?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-33801 published?
CVE-2026-33801 was published on 2026-07-09 and last updated on 2026-07-13.

References

Affected products (8)

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