# CVE-2026-57054: Junos OS: MX Series: Web filtering doesn't block specifically formatted URLs

> Attackers can bypass web filtering on Juniper MX Series devices by using specially formatted URLs, accessing blocked resources.

- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Jul 2026
- **Updated:** 10 Jul 2026
- **Also known as:** GHSA-h62j-crg6-gvwf

## What is CVE-2026-57054?

CVE-2026-57054 is a medium-severity vulnerability in Juniper Junos, published on 9 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-706 (Use of Incorrectly-Resolved Name or Reference)

## Which versions are affected by CVE-2026-57054?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2026-57054?

No fix has been published for CVE-2026-57054 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57054 being exploited?

There is no known exploitation of CVE-2026-57054 in the wild and no public exploit code.

## Other vulnerabilities in Juniper Junos

- [CVE-2023-36845](https://insights.sbomify.com/CVE-2023-36845/): Juniper Junos OS EX Series and SRX Series PHP External Variable Modification (critical 9.8, exploited in the wild)
- [CVE-2020-1631](https://insights.sbomify.com/CVE-2020-1631/): Juniper Junos OS Path Traversal (high 8.8, exploited in the wild)
- [CVE-2025-21590](https://insights.sbomify.com/CVE-2025-21590/): Juniper Junos OS Improper Isolation or Compartmentalization (medium 6.7, exploited in the wild)
- [CVE-2023-36851](https://insights.sbomify.com/CVE-2023-36851/): Juniper Junos OS SRX Series Missing Authentication for Critical Function (medium 5.3, exploited in the wild)
- [CVE-2023-36844](https://insights.sbomify.com/CVE-2023-36844/): Juniper Junos OS EX Series PHP External Variable Modification (medium 5.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57054 and fix it if it is affected.

What it is: CVE-2026-57054 is a medium-severity vulnerability in Juniper Junos, published on 9 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-57054 in the wild and no public exploit code.

Affected product: Juniper Junos. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-57054/ (Markdown: https://insights.sbomify.com/CVE-2026-57054/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57054
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57054
- OSV: https://osv.dev/vulnerability/CVE-2026-57054

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57054/
Summaries are generated and may contain mistakes; the official description above is the record.