Is CVE-2026-0203 being actively exploited?

CVE-2026-0203 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2026-0203?

CVE-2026-0203 has a CVSS 3.1 base score of 6.5 (MEDIUM).

CVE-2026-0203

MEDIUM · CVSS 6.5EPSS 0.3%EU EUVD

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 23.4 before 23.4R2-S3, * from 24.2 before 24.2R1-S2, 24.2R2.

Key facts

CVSS score: 6.5 (v3.1)
Severity: MEDIUM
CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-755
EPSS score: 0.3% (17th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2026-2681)
Published: January 15, 2026
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2026-2681 in the EU Vulnerability Database. Last updated in EUVD on March 10, 2026.

View on the EU Vulnerability Database

Affected products

juniper / junos
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and 39 more…

Certified products that may be affected

5 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Junos Space Network Management Platform, with or without Network Director and with or without Security Director in JA2500 - Juniper Networks, Inc. - FIPS 140 3816 - historical
Juniper Networks SRX345/SRX345-DUAL-AC with Junos 15.1X49-D110 - Juniper Networks, Inc. - FIPS 140 3247 - historical
Junos-FIPS 10.4 L2 OS Cryptographic Module - Juniper Networks, Inc. - FIPS 140 1813 - historical
Junos-FIPS 10.4 L1 OS Cryptographic Module - Juniper Networks, Inc. - FIPS 140 1772 - historical
JUNOS-FIPS - Juniper Networks, Inc. - FIPS 140 602 - historical

References

https://kb.juniper.net/JSA104294(Vendor Advisory)
https://supportportal.juniper.net/JSA104294(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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