Vulnerability-Lookup

GHSA-X6PX-8WP8-5CWQ

Vulnerability from github – Published: 2026-01-15 21:31 – Updated: 2026-01-15 21:31

Details

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.

Severity ?

6.5 (Medium)


                  
                    CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

7.1 (High)


                  
                    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/RE:M/U:Amber

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-0203"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-755"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-01-15T21:16:05Z",
    "severity": "HIGH"
  },
  "details": "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).\n\n\n\nWhen 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.\n\nThis issue only affects ICMPv4. ICMPv6 is not vulnerable to this issue.\n\nThis issue affects Junos OS:\u00a0\n\n\n\n  *  all versions before 21.2R3-S9,\u00a0\n  *  from 21.4 before 21.4R3-S10,\u00a0\n  *  from 22.2 before 22.2R3-S7,\u00a0\n  *  from 22.3 before 22.3R3-S4,\u00a0\n  *  from 22.4 before 22.4R3-S5,\u00a0\n  *  from 23.2 before 23.2R2-S3,\u00a0\n  *  from 23.4 before 23.4R2-S3,\u00a0\n  *  from 24.2 before 24.2R1-S2, 24.2R2.",
  "id": "GHSA-x6px-8wp8-5cwq",
  "modified": "2026-01-15T21:31:48Z",
  "published": "2026-01-15T21:31:48Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-0203"
    },
    {
      "type": "WEB",
      "url": "https://kb.juniper.net/JSA104294"
    },
    {
      "type": "WEB",
      "url": "https://supportportal.juniper.net/JSA104294"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:X/RE:M/U:Amber",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-0203 (GCVE-0-2026-0203)

Vulnerability from cvelistv5 – Published: 2026-01-15 20:17 – Updated: 2026-01-15 21:11

Title

Junos OS: Receipt of a specifically malformed ICMP packet causes an FPC restart

Summary

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.

Severity ?

6.5 (Medium)


                        
                          CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

7.1 (High)


                        
                          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/RE:M/U:Amber

CWE

CWE-755 - Improper Handling of Exceptional Conditions

Assigner

juniper

References

URL

Tags

	https://supportportal.juniper.net/JSA104294	vendor-advisory
	https://kb.juniper.net/JSA104294	vendor-advisory

Impacted products

	Vendor	Product	Version
	Juniper Networks	Junos OS	Affected: 0 , < 21.2R3-S9 (semver) Affected: 21.4 , < 21.4R3-S10 (semver) Affected: 22.2 , < 22.2R3-S7 (semver) Affected: 22.3 , < 22.3R3-S4 (semver) Affected: 22.4 , < 22.4R3-S5 (semver) Affected: 23.2 , < 23.2R2-S3 (semver) Affected: 23.4 , < 23.4R2-S3 (semver) Affected: 24.2 , < 24.2R1-S2, 24.2R2 (semver)

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-0203",
                "options": [
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                    "Exploitation": "none"
                  },
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                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
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                "role": "CISA Coordinator",
                "timestamp": "2026-01-15T21:11:21.932357Z",
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Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-X6PX-8WP8-5CWQ

CVE-2026-0203 (GCVE-0-2026-0203)

Tags

Sightings

Nomenclature