CVE-2025-52986: Junos OS and Junos OS Evolved: When RIB sharding is configured each time a show command is executed RPD memory leaks

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-11 · updated 2026-06-17
Weakness: CWE-401

Description

A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a local, low privileged user to cause an impact to the availability of the device. When RIB sharding is enabled and a user executes one of several routing related 'show' commands, a certain amount of memory is leaked. When all available memory has been consumed rpd will crash and restart. The leak can be monitored with the CLI command: show task memory detail | match task_shard_mgmt_cookie where the allocated memory in bytes can be seen to continuously increase with each exploitation. This issue affects: Junos OS: * all versions before 21.2R3-S9, * 21.4 versions before 21.4R3-S11, * 22.2 versions before 22.2R3-S7, * 22.4 versions before 22.4R3-S7, * 23.2 versions before 23.2R2-S4, * 23.4 versions before 23.4R2-S4, * 24.2 versions before 24.2R2, * 24.4 versions before 24.4R1-S2, 24.4R2; Junos OS Evolved: * all versions before 22.2R3-S7-EVO * 22.4-EVO versions before 22.4R3-S7-EVO, * 23.2-EVO versions before 23.2R2-S4-EVO, * 23.4-EVO versions before 23.4R2-S4-EVO, * 24.2-EVO versions before 24.2R2-EVO, * 24.4-EVO versions before 24.4R2-EVO.

Affected products

Juniper Junos OS: before 21.2; 21.2, 21.2-r1, 21.2-r1-s1, 21.2-r1-s2, 21.2-r2, 21.2-r2-s1 (+79) — fixed in 21.2
Juniper Networks Junos OS Evolved: before 22.2; 22.2, 22.2-r1, 22.2-r1-s1, 22.2-r1-s2, 22.2-r2, 22.2-r2-s1 (+45) — fixed in 22.2

How to fix

Upgrade to a fixed version: Juniper Junos OS 21.2; Juniper Networks Junos OS Evolved 22.2. Check the vendor advisory for mitigations.

References

https://supportportal.juniper.net/JSA100092

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