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JunosOperating system · Juniper

CVE-2026-33782

MEDIUM · 6.5 CVSS v3.1 Published 2026-04-09
Fix available
A fix is available. Upgrade to 22.4 or later.
See remediation →
70/100
Remediation priority · Elevated
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A Missing Release of Memory after Effective Lifetime vulnerability in the DHCP daemon (jdhcpd) of Juniper Networks Junos OS on MX Series, allows an adjacent, unauthenticated attacker to cause a memory leak, that will eventually cause a complete Denial-of-Service (DoS). In a DHCPv6 over PPPoE, or DHCPv6 over VLAN with Active lease query or Bulk lease query scenario, every subscriber logout will leak a small amount of memory. When all available memory has been exhausted, jdhcpd will crash and restart which causes a complete service impact until the process has recovered. The memory usage of jdhcpd can be monitored with: user@host> show system processes extensive | match jdhcpd This issue affects Junos OS: * all versions before 22.4R3-S1, * 23.2 versions before 23.2R2, * 23.4 versions before 23.4R2.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A memory leak vulnerability exists in the DHCP daemon (jdhcpd) of Juniper Junos OS on MX Series. In DHCPv6 over PPPoE or DHCPv6 over VLAN configurations with Active or Bulk lease query enabled, each subscriber logout fails to release allocated memory. Over time, this causes jdhcpd memory usage to grow until the process exhausts all available memory, crashes, and restarts, resulting in complete service disruption until recovery.

MitigationUpgrade Junos OS to version 22.4R3-S1, 23.2R2, 23.4R2 or later. As a workaround, monitor jdhcpd memory usage via 'show system processes extensive | match jdhcpd' and plan maintenance windows for upgrades.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
JunosOperating system
Affected:< 22.4= 22.4= 23.2= 23.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device is MX Series
    Run 'show chassis hardware' or 'show system information' and verify the device model is an MX Series router
    Affected if Device is not an MX Series - the vulnerability only affects MX Series
  2. Check Junos OS version
    Run 'show version' and compare the installed version against affected ranges: versions < 22.4, = 22.4, = 23.2, = 23.4
    Affected if Version matches < 22.4, 22.4, 23.2, or 23.4 exactly - later versions like 22.4R3-S1, 23.2R2, 23.4R2 are not affected
  3. Verify DHCPv6 over PPPoE or VLAN configuration
    Run 'show configuration protocols dhcpv6' and look for PPPoE or VLAN-related interface configurations under the DHCPv6 protocol
    Affected if DHCPv6 over PPPoE or DHCPv6 over VLAN is configured - this is required for the vulnerability to manifest
  4. Confirm Active or Bulk lease query is enabled
    Run 'show configuration protocols dhcpv6' and search for 'lease-query' or 'bulk-lease-query' statements at the [edit protocols dhcpv6] hierarchy
    Affected if Active lease-query or bulk-lease-query is enabled - this feature must be present for the memory leak to occur
  5. Monitor jdhcpd memory usage
    Run 'show system processes extensive | match jdhcpd' repeatedly over time and observe if RES memory usage continuously grows without stabilizing
    Affected if jdhcpd memory usage steadily increases and approaches system limits - indicates active memory leak from this vulnerability

Device is affected only if it is an MX Series running a vulnerable Junos version (22.4, 23.2, or 23.4) with DHCPv6 over PPPoE/VLAN configured AND Active/Bulk lease query enabled, showing growing jdhcpd memory consumption.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 22.4 or later
Fixed in 22.4
Interim mitigation

Upgrade Junos OS to version 22.4R3-S1, 23.2R2, 23.4R2 or later. As a workaround, monitor jdhcpd memory usage via 'show system processes extensive | match jdhcpd' and plan maintenance windows for upgrades.

Recommended fix High confidence

22.4R3-S1, 23.2R2, or 23.4R2 (select based on existing release compatibility)

  1. Verify current Junos OS version with 'show version'
  2. Confirm the device is an MX Series platform
  3. Plan upgrade to a fixed release: 22.4R3-S1, 23.2R2, or 23.4R2 (choose based on compatibility requirements)
  4. Back up current configuration with 'request system snapshot'
  5. Upgrade Junos OS using standard procedures (e.g., 'request system software add <package>')
  6. Reboot the device after upgrade completes
  7. Verify jdhcpd process is running normally with 'show system processes extensive | match jdhcpd'
  8. Monitor memory usage of jdhcpd periodically to confirm the leak is resolved

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Junos Scoped from the published advisory
  • Consultation12.0 h
  • Implementation6.0 h
  • Testing10.0 h
  • Review / QA6.0 h
34.0 hours of engineering $6,060
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33782 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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