How severe is CVE-2026-33797?

CVE-2026-33797 has a CVSS 3.x base score of 7.4, rated high 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-2026-33797 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33797?

CVE-2026-33797 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-2026-33797?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-33797 have an EU (EUVD) identifier?

Yes. CVE-2026-33797 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21208.

When was CVE-2026-33797 published?

CVE-2026-33797 was published on 2026-04-09 and last updated on 2026-06-17.

CVE-2026-33797

CVE-2026-33797 is a high-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 7.4. 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.4)
CVSS v4: 7.1
EPSS exploit prediction: 0% (6th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21208
Weakness: CWE-20
Affected product: Juniper Junos
Published: 2026-04-09
Last modified: 2026-06-17

Description

An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS). An attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS: * 25.2 versions before 25.2R2 This issue does not affect Junos OS versions before 25.2R1. This issue affects Junos OS Evolved: * 25.2-EVO versions before 25.2R2-EVO This issue does not affect Junos OS Evolved versions before 25.2R1-EVO. eBGP and iBGP are affected. IPv4 and IPv6 are affected.

Frequently asked questions

What is CVE-2026-33797?: An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS). An attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS: * 25.2 versions before 25.2R2 This issue does not affect Junos OS versions before 25.2R1. This issue affects Junos OS Evolved: * 25.2-EVO versions before 25.2R2-EVO This issue does not affect Junos OS Evolved versions before 25.2R1-EVO. eBGP and iBGP are affected. IPv4 and IPv6 are affected.
How severe is CVE-2026-33797?: CVE-2026-33797 has a CVSS 3.x base score of 7.4, rated high 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-2026-33797 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33797?: CVE-2026-33797 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-2026-33797?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-33797 have an EU (EUVD) identifier?: Yes. CVE-2026-33797 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21208.
When was CVE-2026-33797 published?: CVE-2026-33797 was published on 2026-04-09 and last updated on 2026-06-17.

References

Affected products (8)

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:*:*:*:*:*:*

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