CVE-2026-102078 Junos OS: SRX Series: A high volume of DNS traffic over TCP can lead to a flowd crash
An unauthenticated attacker can cause a denial of service on Juniper SRX devices by sending high volumes of DNS traffic when web filtering is enabled.
- 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-2026-102078?
CVE-2026-102078 is a high-severity use after free vulnerability in Juniper Networks Junos OS, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A Use After Free vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).
When web filtering for TCP traffic is configured, a high volume of DNS requests increases the likelihood of a flowd crash and restart, which leads to a complete service outage until the service has automatically recovered. This is a race condition outside the attacker's direct control.
This issue affects Junos OS on SRX Series:
* All versions before 23.2R2-S5; * from 23.4 before 23.4R2-S6; * from 24.2 before 24.2R2-S3; * from 24.4 before 24.4R2-S1; * from 25.2 before 25.2R1-S1, 25.2R2.
Weakness: CWE-416
Which versions are affected by CVE-2026-102078?
How do I fix CVE-2026-102078?
No fix has been published for CVE-2026-102078 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-102078 being exploited?
There is no known exploitation of CVE-2026-102078 in the wild and no public exploit code.
Sources
Also known as GHSA-vwc2-r92q-mf9c.