# 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.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/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:** 14 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-vwc2-r92q-mf9c

## 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 (Use After Free)

## 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.

## Is CVE-2026-102078 being exploited?

There is no known exploitation of CVE-2026-102078 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102078 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-102078 in the wild and no public exploit code.

Affected product: Juniper Networks Junos OS. 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-2026-102078/ (Markdown: https://insights.sbomify.com/CVE-2026-102078/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102078
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102078
- OSV: https://osv.dev/vulnerability/CVE-2026-102078

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102078/
Summaries are generated and may contain mistakes; the official description above is the record.