CVE-2026-57029

Published Jul 9, 2026

Last updated 9 days ago

Overview

Description
A Missing Synchronization vulnerability in the flow collector handler of Juniper Networks Junos OS Evolved on QFX Series allows an adjacent, unauthenticated attacker to cause a Denial-of-Service (DoS). When the reachability of an sFlow collector changes, the corresponding next-hop entry is updated. If this update occurs simultaneously with the sFlow thread accessing the next-hop data (which is outside the attackers control), it causes the evo-pfemand process to crash, impacting all traffic forwarding until the automatic process restart has completed. This issue affects Junos OS Evolved on QFX Series: * all 23.2 versions,  * 23.4 versions before 23.4R2-S7-EVO, * 24.2 versions before 24.2R2-S5-EVO, * 24.4 versions before 24.4R2-S3-EVO, * 25.2 versions before 25.2R2-EVO.
Source
sirt@juniper.net
NVD status
Analyzed
Products
junos_os_evolved

Risk scores

CVSS 4.0

Type
Secondary
Base score
6
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:M/U:X
Severity
MEDIUM

CVSS 3.1

Type
Secondary
Base score
5.3
Impact score
3.6
Exploitability score
1.6
Vector string
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

sirt@juniper.net
CWE-820

Social media

Hype score
Not currently trending

Configurations

References

Sources include official advisories and independent security research.