# CVE-2026-103993: Memory corruption in Junos OS

> An adjacent attacker can crash the routing daemon by sending specific BGP communities, causing a denial of service on Juniper devices.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-3vcp-3vfh-hjrh

## What is CVE-2026-103993?

CVE-2026-103993 is a medium-severity memory corruption vulnerability in Juniper Networks Junos OS, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An Out-of-bounds Write vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent attacker which sends a specific set of BGP communities to cause a Denial-of-Service (DoS) as rpd crashes when graceful-shutdown sender community is added when attempting to advertise.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-103993?


## How do I fix CVE-2026-103993?

No fix has been published for CVE-2026-103993 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103993 being exploited?

There is no known exploitation of CVE-2026-103993 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103993 and fix it if it is affected.

What it is: CVE-2026-103993 is a medium-severity memory corruption vulnerability in Juniper Networks Junos OS, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-103993 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-2026-103993/ (Markdown: https://insights.sbomify.com/CVE-2026-103993/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103993
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103993
- OSV: https://osv.dev/vulnerability/CVE-2026-103993

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103993/
Summaries are generated and may contain mistakes; the official description above is the record.