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Full vulnerability report · 2026
CVE-2026-57054High confidence

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

Juniper Networks · Junos OS

6.9MediumCVSS 4.0
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.37% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Juniper Networks Junos OS and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-42724

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

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.

What

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.

Why

The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Use of Incorrectly-Resolved Name or Reference → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-706 ↗

CWE-706: Use of Incorrectly-Resolved Name or Reference. The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
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/AU:Y/RE:M

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SILowSubsequent-system integrity: A successful attack can cause a limited loss.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-706
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-2257Juniper JUNOS und JUNOS Evolved: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Juniper JUNOS, JUNOS Evolved, Juniper EX Series, Juniper MX Series, Juniper QFX Series und Juniper SRX Series ausnutzen, um einen Denial of Service Zustand herbeizuführen, um Informationen offenzulegen, um Code auszuführen und um ein undefiniertes Verhalten auszulösen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0852Multiples vulnérabilités dans les produits Juniper Networks

s CVE-2026-57024 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57025 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57026 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57027 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57028 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57029 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57030 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57031 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57032 du 08 juillet 2026 Bulletin de sécurité Juniper Networks CVE-2026-57054 du 08 juillet 2026 Une gestion de version détaillée se trouve à la fin de ce document. Risques Atteinte à la confidentialité des données Contournement de la politique de sécurité Déni de service à distance Exécution de code arbitraire Non spécifié par l'éditeur Systèmes affectés cRPD versions antérieures à 26.2R1 CTPView versions antérieures à 9.3R2-3 Junos OS Evolved versions 21.2R3-x antérieures à 21.2R3-S8-EVO Junos OS Evolved versions 21.4R3-x antérieures à 21.4R3-S7-EVO Junos OS Evolved versions 22.2R3-x antérieures à 22.2R3-S4-EVO Junos OS Evolved versions 22.3R3-x antérieures à 22.3R3-S3-EVO Junos OS Evolved versions 22.4R3-x antérieu

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-023641ジュニパーネットワークスのJunos OSにおける誤って解決された名前や参照の使用に関する脆弱性

Juniper Networks Junos OSのMXシリーズにおけるURLフィルタリングプラグインには、誤って解決された名前または参照の使用に関する脆弱性があります。この脆弱性により、認証されていないネットワークベースの攻撃者がウェブフィルタリングを回避し、本来アクセスできないはずの下流のリソースにアクセスできてしまいます。MXシリーズデバイスでウェブフィルタリングが設定されている場合、攻撃者が特定の形式で構成されたURLを含むリクエストを送信すると、システムがブロックするように設定されていてもそのリクエストが転送されてしまいます。その結果、攻撃者は本来アクセスできないはずの下流のリソースにアクセスできることになります。この問題は以下のJunos OS on MXシリーズのバージョンに影響を及ぼします。 * 23.2R2-S7以前のすべてのバージョン * 23.4R2-S8以前の23.4バージョン * 24.2R2-S5以前の24.2バージョン * 24.4R2-S4以前の24.4バージョン * 25.2R2-S1以前の25.2バージョン * 25.4R1-S2および25.4R2以前の25.4バージョンです。

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0224Kwetsbaarheden verholpen in Juniper Networks Junos OS en Junos OS Evolved

A vulnerability in the URL filtering plugin of Juniper Networks Junos OS on MX Series allows unauthenticated attackers to bypass web filtering and access restricted downstream resources via specially crafted URL requests.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Junos OS: < 23.2R2-S7, 23.4 < 23.4R2-S8, 24.2 < 24.2R2-S5, 24.4 < 24.4R2-S4, 25.2 < 25.2R2-S1, 25.4 < 25.4R1-S2, 25.4R2
Fixed
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 9 Jul 2026 · Last source change 10 Jul 2026, 14:34 UTC · CWE-706 · Use of Incorrectly-Resolved Name or Reference

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-42724
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-57054 · cve.blacktree.nl