# CVE-2026-101939: Null dereference in Junos OS

> A remote attacker can cause a denial of service in the routing daemon by sending a BGP update when a specific non-existent routing table is referenced in source-based forwarding policies.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/V:C/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:** 16 Oct 2026
- **Also known as:** GHSA-jw62-w37q-cc69

## What is CVE-2026-101939?

CVE-2026-101939 is a high-severity 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 NULL Pointer Dereference vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows a configured peer sending a BGP UPDATE to cause a denial of service when an import policy with `then source-based-forwarding next-hop next-table <X>` is configured to reference a routing table that does not exist.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-101939?


## How do I fix CVE-2026-101939?

No fix has been published for CVE-2026-101939 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-101939 being exploited?

There is no known exploitation of CVE-2026-101939 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-101939 and fix it if it is affected.

What it is: CVE-2026-101939 is a high-severity 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-2026-101939 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-2026-101939/ (Markdown: https://insights.sbomify.com/CVE-2026-101939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-101939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-101939
- OSV: https://osv.dev/vulnerability/CVE-2026-101939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-101939/
Summaries are generated and may contain mistakes; the official description above is the record.