Stack-based buffer overflow in Junos OS Evolved - CVE-2025-59969

Detailed vulnerability description

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to stack-based buffer overflow in the advanced forwarding toolkit (evo-aftmand/evo-pfemand) when processing crafted multicast packets. A remote attacker can send crafted multicast packets to cause a denial of service.

Exposure requires the [ protocols mld ] or [ protocols pim ] configuration.

How to mitigate CVE-2025-59969

Install security update from vendor's website.

This issue affects Junos OS Evolved PTX Series:

• All versions before 22.4R3-S8-EVO,
• from 23.2 before 23.2R2-S5-EVO,
• from 23.4 before 23.4R2-EVO,
• from 24.2 before 24.2R2-EVO,
• from 24.4 before 24.4R2-EVO.

This issue affects Junos OS Evolved on QFX5000 Series:

• 22.2-EVO version before 22.2R3-S7-EVO,
• 22.4-EVO version before 22.4R3-S7-EVO,
• 23.2-EVO versions before 23.2R2-S4-EVO,
• 23.4-EVO versions before 23.4R2-S5-EVO,
• 24.2-EVO versions before 24.2R2-S1-EVO,
• 24.4-EVO versions before 24.4R1-S3-EVO, 24.4R2-EVO.

This issue does not affect Junos OS Evolved on QFX5000 Series versions before: 21.2R2-S1-EVO, 21.2R3-EVO, 21.3R2-EVO, 21.4R1-EVO, and 22.1R1-EVO.

Sources

• https://supportportal.juniper.net/s/article/2026-04-Security-Bulletin-Junos-OS-Evolved-QFX5000-Series-and-PTX-Series-An-attacker-sending-crafted-multicast-packets-will-cause-evo-aftmand-evo-pfemand-to-crash-and-restart-CVE-2025-59969