CVE-2026-57054

Junos OS: MX Series: Web filtering doesn't block specifically formatted URLs

MEDIUM

5.8

CVSS Score

Published: July 9, 2026 at 09:14 PM UTC

Updated: October 25, 2026 at 03:10 PM UTC

1 product affected across 1 vendorJunos· also runs on 11 platforms

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Severity

MEDIUM5.8

Exploit prediction

EPSS 0.4%

SSVC

No known exploit

Description

A Use of Incorrectly-Resolved Name or Reference vulnerability in the URL filtering plugin of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass web filtering and access downstream resources that should be unreachable. If an MX Series device is configured with web filtering, and an attacker sends a request with a specifically formatted URL, this request will get forwarded despite the system being configured to block it. In turn, an attacker can access downstream resources that are expected to be unreachable. This issue affects Junos OS on MX Series: * all versions before 23.2R2-S7, * 23.4 versions before 23.4R2-S8, * 24.2 versions before 24.2R2-S5, * 24.4 versions before 24.4R2-S4, * 25.2 versions before 25.2R2-S1, * 25.4 versions before 25.4R1-S2, 25.4R2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

Affected range stops below 23.2, so it looks safe — our inference, not a vendor statement

Affected range stops below 23.2R2-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 23.4R2-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 24.2R2-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 24.4R2-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 25.2R2-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 25.4R1-S2, 25.4R2, so it looks safe — our inference, not a vendor statement

juniper-mx10004 (environment) · juniper-mx10008 (environment) · juniper-mx2008 (environment) · juniper-mx2010 (environment) · juniper-mx2020 (environment) · juniper-mx204 (environment) · juniper-mx240 (environment) · juniper-mx301 (environment) · juniper-mx304 (environment) · juniper-mx480 (environment) · juniper-mx960 (environment)