Juniper Junos OS up to 25.2R1 Packet Forwarding Engine memory leak

Summaryinfo

A vulnerability classified as critical has been found in Juniper Junos OS up to 23.4R2-S6/24.2R2-S2/24.4R2-S2/25.2R1-S1/25.2R1. Affected is an unknown function of the component Packet Forwarding Engine. Performing a manipulation results in memory leak. This vulnerability is identified as CVE-2026-102081. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Juniper Junos OS up to 23.4R2-S6/24.2R2-S2/24.4R2-S2/25.2R1-S1/25.2R1. This affects some unknown processing of the component Packet Forwarding Engine. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on availability. The summary by CVE is:

A Missing Release of Memory after Effective Lifetime vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial-of-Service (DoS). On SRX4000 Series, and SRX5000 Series with SPC3, and MX Series with SPC3, when one or more specific application services like ALGs, IDP/DPI, APPID, SECINTEL, AAMW or AppQoE are configured, a high connections per second churn will cause PFE memory to leak. If the memory is exhausted traffic processing will be impacted. Use the CLI command show security monitoring to monitor the memory utilization of the PFEs on the FPCs. This issue affects Junos OS on SRX Series and MX Series: * 23.4 versions from 23.4R2-S3 before 23.4R2-S7; * 24.2 versions from 24.2R2 before 24.2R2-S3; * 24.4 versions before 24.4R2-S3; * 25.2 versions before 25.2R1-S2, 25.2R2.

It is possible to read the advisory at supportportal.juniper.net. This vulnerability is uniquely identified as CVE-2026-102081 since 09/28/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/14/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 23.4R2-S7, 24.2R2-S3, 24.4R2-S3, 25.2R1-S2 or 25.2R2 eliminates this vulnerability.

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Productinfo

Type

• Router Operating System

Vendor

• Juniper

Name

• Junos OS

Version

• 23.4R2-S6
• 24.2R2-S2
• 24.4R2-S2
• 25.2R1
• 25.2R1-S1

License

• commercial

Website

• Vendor: https://www.juniper.net/

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