CVE-2026-57054
Juniper Junos ≤ 23.2
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:M/U:XSummary
CVE-2026-57054 is a medium-severity Use of Incorrectly-Resolved Name or Reference (CWE-706) vulnerability in Juniper Junos. Its CVSS base score is 6.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 14th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SC-7 (Boundary Protection) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-42724
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability allows unauthenticated network-based attackers to bypass web filtering controls on Juniper MX Series devices, directly enabling exploitation of a public-facing application to access restricted downstream resources.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
SC-7 enforces boundary protection that can block or redirect network traffic attempting to bypass the URL filtering plugin on MX Series devices.
AC-4 enforces information flow policies so that requests with malformed URLs are still subject to the configured web-filtering rules rather than being forwarded.
SI-4 enables continuous monitoring of network traffic and security functions, allowing detection of URL-filter bypass attempts on MX Series platforms.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices directly prevent incorrect name/reference resolution bugs during coding.
Enforced authorization boundaries limit damage from an incorrectly resolved reference.
Logical segmentation and access controls reduce the chance an out-of-sphere resolution succeeds.
Hardened configuration baselines can constrain allowable name-to-resource mappings.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect incorrect name or reference resolution through fuzzing and negative test cases.
Network segmentation and routing policies reduce the chance that a mis-resolved name leads to an unintended external resource.
Segregated networks limit the blast radius when a name or reference resolves outside the intended control sphere.
Secure SDLC practices include design reviews that can catch incorrect name or reference handling before deployment.
Application security requirements can mandate validation of all external references and names used at runtime.
Secure architecture principles discourage reliance on ambient or globally-resolvable names without explicit scoping.