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 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 23.4 before 23.4R2-S3,
* from 24.2 before 24.2R1-S2, 24.2R2.
Metrics
Affected Vendors & Products
No advisories yet.
Solution
The following software releases have been updated to resolve this specific issue: Junos OS 20.2R3-S10, 21.2R3-S9, 21.4R3-S10, 22.2R3-S7, 22.3R3-S4, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3, 24.2R1-S2, 24.2R2, 24.4R1, and all subsequent releases.
Workaround
There are no known workarounds for this issue.
Thu, 15 Jan 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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 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 23.4 before 23.4R2-S3, * from 24.2 before 24.2R1-S2, 24.2R2. | |
| Title | Junos OS: Receipt of a specifically malformed ICMP packet causes an FPC restart | |
| Weaknesses | CWE-755 | |
| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: juniper
Published:
Updated: 2026-01-15T21:11:32.119Z
Reserved: 2025-10-29T20:57:34.631Z
Link: CVE-2026-0203
No data.
Status : Received
Published: 2026-01-15T21:16:05.457
Modified: 2026-01-15T21:16:05.457
Link: CVE-2026-0203
No data.
OpenCVE Enrichment
No data.