# CVE-2025-52949: Junos OS and Junos OS Evolved: In an EVPN environment, receipt of specifically malformed BGP update causes RPD crash

> A malformed BGP packet can crash the routing daemon in EVPN-enabled Junos OS devices, causing a denial of service.

- **Severity:** High 7.1 (`CVSS:4.0/AV:A/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/U:Amber`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jul 2025
- **Updated:** 11 Jul 2025
- **Also known as:** GHSA-fx8c-8vrh-7hg5

## What is CVE-2025-52949?

CVE-2025-52949 is a high-severity denial of service vulnerability in Juniper Junos, published on 11 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An Improper Handling of Length Parameter Inconsistency vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a logically adjacent BGP peer sending a specifically malformed BGP packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.

Only systems configured for Ethernet Virtual Private Networking (EVPN) signaling are vulnerable to this issue. 

This issue affects iBGP and eBGP, and both IPv4 and IPv6 are affected by this vulnerability.This issue affects:

Junos OS: 

  *  all versions before 21.4R3-S11, 
  *  from 22.2 before 22.2R3-S7, 
  *  from 22.4 before 22.4R3-S7, 
  *  from 23.2 before 23.2R2-S4, 
  *  from 23.4 before 23.4R2-S5, 
  *  from 24.2 before 24.2R2-S1, 
  *  from 24.4 before 24.4R1-S3, 24.4R2; 

Junos OS Evolved: 

  *  all versions before 22.2R3-S7-EVO, 
  *  from 22.4-EVO before 22.4R3-S7-EVO, 
  *  from 23.2-EVO before 23.2R2-S4-EVO, 
  *  from 23.4-EVO before 23.4R2-S5-EVO, 
  *  from 24.2-EVO before 24.2R2-S1-EVO, 
  *  from 24.4-EVO before 24.4R1-S3-EVO, 24.4R2-EVO.

Weakness: CWE-130 (Improper Handling of Length Parameter Inconsistency)

## Which versions are affected by CVE-2025-52949?

It affects 2 products.


Products: Juniper Junos, Juniper Junos Os Evolved.

## How do I fix CVE-2025-52949?

No fix has been published for CVE-2025-52949 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-52949 being exploited?

There is no known exploitation of CVE-2025-52949 in the wild and no public exploit code.

## Other vulnerabilities in Juniper Junos

- [CVE-2023-36845](https://insights.sbomify.com/CVE-2023-36845/): Juniper Junos OS EX Series and SRX Series PHP External Variable Modification (critical 9.8, exploited in the wild)
- [CVE-2020-1631](https://insights.sbomify.com/CVE-2020-1631/): Juniper Junos OS Path Traversal (high 8.8, exploited in the wild)
- [CVE-2025-21590](https://insights.sbomify.com/CVE-2025-21590/): Juniper Junos OS Improper Isolation or Compartmentalization (medium 6.7, exploited in the wild)
- [CVE-2023-36851](https://insights.sbomify.com/CVE-2023-36851/): Juniper Junos OS SRX Series Missing Authentication for Critical Function (medium 5.3, exploited in the wild)
- [CVE-2023-36844](https://insights.sbomify.com/CVE-2023-36844/): Juniper Junos OS EX Series PHP External Variable Modification (medium 5.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-52949 and fix it if it is affected.

What it is: CVE-2025-52949 is a high-severity denial of service vulnerability in Juniper Junos, published on 11 Jul 2025. 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-2025-52949 in the wild and no public exploit code.

Affected product: Juniper Junos. 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-2025-52949/ (Markdown: https://insights.sbomify.com/CVE-2025-52949/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-52949
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-52949
- OSV: https://osv.dev/vulnerability/CVE-2025-52949

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-52949/
Summaries are generated and may contain mistakes; the official description above is the record.