CVE-2026-0203
6.5 · MEDIUMOverview
CVE-2026-0203 is a medium-severity vulnerability affecting juniper junos. It was published on January 15, 2026 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
Technical Description
An Improper Handling of Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS allows an unauthenticated, network-adjacent attacker sending a specifically malformed ICMP packet to cause an FPC to crash and restart, resulting in a Denial of Service (DoS).
When an ICMP packet is received with a specifically malformed IP header value, the FPC receiving the packet crashes and restarts. Due to the specific type of malformed packet, adjacent upstream routers would not forward the packet, limiting the attack surface to adjacent networks.
This issue only affects ICMPv4. ICMPv6 is not vulnerable to this issue.
This issue does not affect AFT-based line cards such as the MPC10, MPC11, LC4800, LC9600, and MX304.
This issue affects Junos OS:
* all versions before 21.2R3-S9,
* from 21.4 before 21.4R3-S10,
* from 22.2 before 22.2R3-S7,
* from 22.3 before 22.3R3-S4,
* from 22.4 before 22.4R3-S5,
* from 23.2 before 23.2R2-S3,
* from 2
Remediation
Check the references section for vendor advisories and patches from juniper. Update junos to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| juniper | junos | >= 0, < 21.2 | Affected |
Frequently Asked Questions
What is CVE-2026-0203?
CVE-2026-0203 is a medium-severity vulnerability affecting juniper junos. It was published on January 15, 2026 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
How severe is CVE-2026-0203?
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-0203?
Check the references section for vendor advisories and patches from juniper. Update junos to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-0203?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-0203 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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