CVE-2026-33782 Junos OS: MX Series: In specific DHCPv6 scenarios jdhcpd memory increases continuously with subscriber logouts
An adjacent attacker can cause a memory leak in the DHCP daemon leading to a denial of service in specific DHCPv6 scenarios.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33782?
CVE-2026-33782 is a high-severity denial of service vulnerability in Juniper Junos, published on 9 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-401
Which versions are affected by CVE-2026-33782?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2026-33782?
No fix has been published for CVE-2026-33782 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-33782 being exploited?
There is no known exploitation of CVE-2026-33782 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-rpvg-7w65-9g7p.