CVE-2026-57029
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk9th percentile - higher than 9% of all known CVEs
Summary
A missing synchronization vulnerability in the sFlow collector handler of Junos OS Evolved on QFX Series allows an unauthenticated adjacent attacker to cause a Denial-of-Service (DoS). When the reachability of an sFlow collector changes and the sFlow thread simultaneously accesses next-hop data, the evo-pfemand process crashes, blocking traffic forwarding until automatic restart.
Risk Assessment
The attack can disrupt QFX switch operations, halting all network traffic forwarding and causing significant network downtime.
Recommendation
Immediately upgrade Junos OS Evolved to version 23.4R2-S7-EVO, 24.2R2-S5-EVO, 24.4R2-S3-EVO, 25.2R2-EVO or later as per the fixed versions list.
Other vulnerabilities in Junos OS Evolved
See all- CVE-2026-57028High
An Improper Restriction of Communication Channel to Intended Endpoints vulnerability in Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause license exhaustion. Due to incorrect initialization, a process that should only communicate internally can be reached over the network via an open port, leading to unauthorized access to license management.
- CVE-2026-33803Medium
A vulnerability in Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause limited information disclosure and availability impact. Due to incorrect initialization, an internal process is exposed over the network via an open port.
- CVE-2026-33794Medium
A vulnerability in the advanced forwarding toolkit (evo-aftmand) of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated network-based attacker to generate continuous routing updates, causing the evo-aftmand process on the PFE to crash, leading to a Denial-of-Service (DoS). Successful exploitation depends on a sequence of events outside the attacker's direct control.
- CVE-2026-33788High
Missing authentication for a critical function in FPCs of Junos OS Evolved on PTX series allows a local authenticated attacker with low privileges to gain direct access to FPCs as a high-privileged user, potentially leading to full compromise.
Original NVD description (English source)
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.