CVE-2026-33797
Junos OS and Junos OS Evolved: An attacker sending a specific genuine BGP packet causes a BGP reset
- State
- Published
- Severity
- 7.1 High
- Published
- Apr 9, 2026
- Updated
- Apr 23, 2026
- Reserved
- Mar 23, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.1 High | 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/V:C/RE:M/U:Green | juniper |
| 3.1 | 7.4 High | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H | juniper |
Weaknesses
- CWE-20 Improper Input Validation
Affected Products
| Product | Versions |
|---|---|
Junos OSJuniper Networks |
|
Junos OS EvolvedJuniper Networks |
|
References
- https://kb.juniper.net/JSA107850vendor-advisory
- https://supportportal.juniper.net/JSA107850vendor-advisory
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