CVE-2023-44186Network attack vector

Sustained routing outage via long AS PATH

Published Oct 11, 2023 · Updated Dec 3, 2024

Improper exceptional-condition handling in affected Junos OS and Junos OS Evolved releases allows remote attackers to crash rpd via BGP. During AS PATH processing, rpd fails while translating a long path containing many 4-byte AS numbers for advertisement to a neighbor that lacks 4-byte-AS support. The path requires NSR, such a legacy BGP neighbor, and continued receipt and advertisement of matching updates, which sustains the routing-service outage; SRX Series devices are excluded because they do not support NSR.

CVSS severity7.5
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper exceptional-condition handling in affected Junos OS and Junos OS Evolved releases allows remote attackers to crash rpd via BGP. During AS PATH processing, rpd fails while translating a long path containing many 4-byte AS numbers for advertisement to a neighbor that lacks 4-byte-AS support. The path requires NSR, such a legacy BGP neighbor, and continued receipt and advertisement of matching updates, which sustains the routing-service outage; SRX Series devices are excluded because they do not support NSR.

The record

CVE
CVE-2023-44186
Published
Oct 11, 2023
Updated
Dec 3, 2024
Vendor
Juniper Networks
Product
Junos OS Evolved
Classifications
CWE-755, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <20.4R3-S8-EVO
  2. Affected versionversion=21.1 <21.1*-EVO
  3. Affected versionversion=21.2 <21.2R3-S6-EVO
  4. Affected versionversion=21.3 <21.3R3-S5-EVO
  5. Affected versionversion=21.4 <21.4R3-S5-EVO
  6. Affected versionversion=22.1 <22.1R3-S4-EVO
  7. Affected versionversion=22.2 <22.2R3-S2-EVO
  8. Affected versionversion=22.3 <22.3R2-S2-EVO, 22.3R3-S1-EVO
  9. Affected versionversion=22.4 <22.4R2-S1-EVO, 22.4R3-EVO

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OS Evolvedversion=0 <20.4R3-S8-EVO; version=21.1 <21.1*-EVO; version=21.2 <21.2R3-S6-EVO; version=21.3 <21.3R3-S5-EVO; version=21.4 <21.4R3-S5-EVO; version=22.1 <22.1R3-S4-EVO; version=22.2 <22.2R3-S2-EVO; version=22.3 <22.3R2-S2-EVO, 22.3R3-S1-EVO; version=22.4 <22.4R2-S1-EVO, 22.4R3-EVO
Juniper Networks · Junos OSversion=0 <20.4R3-S8; version=21.1R1 <21.1*; version=21.2 <21.2R3-S6; version=21.3 <21.3R3-S5; version=21.4 <21.4R3-S5; version=22.1 <22.1R3-S4; version=22.2 <22.2R3-S2; version=22.3 <22.3R2-S2, 22.3R3-S1; version=22.4 <22.4R2-S1, 22.4R3

Published CVSS scores

7.5Juniper NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-755Improper Handling of Exceptional Conditions
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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