CVE Tools
Track your stack

CVE-2026-101986

Junos OS and Junos OS Evolved: J-Web permits pre-authentication CGI execution

No known exploitation. EPSS puts it in the 46th percentile. Fixed versions are out.

CVSS 3.19.8CriticalEPSS percentile46th0.5% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFix3 products8 fixed builds listed below
Check it yourself

OpenVAS · 2 checks

e.g. OID 1.3.6.1.4.1.25623.1.0.158206

Run the check

Published Updated Sources: CVE.org, NVD

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • Juniper Networks Junos OSAffected: < 23.2R2-S7.7Upgrade to: 23.2R2-S7.7Affected: ≥ 23.4, < 23.4R2-S8.13Upgrade to: 23.4R2-S8.13Affected: ≥ 24.2, < 24.2R2-S5.5Upgrade to: 24.2R2-S5.5Affected: ≥ 24.4, < 24.4R2-S5Upgrade to: 24.4R2-S5 + 3 more branchesStated by: CVE record
  • Juniper Networks Junos OS EvolvedAffected: < 23.2R2-S7.7-EVOUpgrade to: 23.2R2-S7.7-EVOAffected: ≥ 23.4, < 23.4R2-S8.11-EVOUpgrade to: 23.4R2-S8.11-EVOAffected: ≥ 24.2, < 24.2R2-S5.6-EVOUpgrade to: 24.2R2-S5.6-EVOAffected: ≥ 24.4, < 24.4R2-S5-EVOUpgrade to: 24.4R2-S5-EVO + 6 more branchesStated by: CVE record
  • Juniper JunosAffected: ≤ 23.1Upgrade to: after 23.1Stated by: NVD

Versions as the sources state them. Full version matrix after sign-in

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

An Improper Authentication vulnerability in J-Web of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network attacker to bypass J-Web authentication and execute CGI content with elevated privileges via a crafted HTTP request.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS46th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.5% chance of exploitation activity in the next 30 days, which ranks it in the 46th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

19 events over 16 days, from the signal feeds we watch.

  1. Patch availableworkaround available, record updated
  2. OpenVAS check added
  3. Patch availablepatch available, workaround available, workaround available, record updated, record updated
  4. Patch availablepatch available, workaround available, workaround available, published, weakness classified, att&ck mapped, record updated, record updated

Affected products

And 1 more affected product. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Scored 9.8 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for Junos OS, not every advisory.