Vulnerabilities

Vulnerability · CVE-2024-39555

An Improper Handling of Exceptional Conditions vulnerability in the Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an attacker…

Published Jul 10, 2024 · catalog updated Jun 17, 2026 · the affected product

Last checked Nov 7, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2024-39555. EPSS is 0.50%. Act only if a listed version of the affected product is installed.

Gaps on this record

  • No plain product name is stored. The page cannot tell you which product to check.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High8.7
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.50%
Remediation
Version ranges on file
Affected products
cpe juniper/junos

An Improper Handling of Exceptional Conditions vulnerability in the Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an attacker sending a specific malformed BGP update message to cause the session to reset, resulting in a Denial of Service (DoS). Continued receipt and processing of these malformed BGP update messages will create a sustained Denial of Service (DoS) condition. Upon receipt of a BGP update message over an established BGP session containing a specifically malformed tunnel encapsulation attribute, when segment routing is enabled, internal processing of the malformed attributes within the update results in improper parsing of remaining attributes, leading to session reset: BGP SEND Notification code 3 (Update Message Error) subcode 1 (invalid attribute list) Only systems with segment routing enabled are vulnerable to this issue. This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations, and requires a remote attacker to have at least one established BGP session. This issue affects: Junos OS: * All versions before 21.4R3-S8, * from 22.2 before 22.2R3-S4, * from 22.3 before 22.3R3-S3, * from 22.4 before 22.4R3-S3, * from 23.2 before 23.2R2-S1, * from 23.4 before 23.4R1-S2, 23.4R2. Junos OS Evolved: * All versions before 21.4R3-S8-EVO, * from 22.2-EVO before 22.2R3-S4-EVO, * from 22.3-EVO before 22.3R3-S3-EVO, * from 22.4-EVO before 22.4R3-S3-EVO, * from 23.2-EVO before 23.2R2-S1-EVO, * from 23.4-EVO before 23.4R1-S2-EVO, 23.4R2-EVO.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe juniper/junos21.4
  • cpe juniper/junos< 21.4

How to fix CVE-2024-39555

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2024-39555. EPSS is 0.50%. Act only if a listed version of the affected product is installed.

Which versions are affected?

Compare what you have installed with 21.4, < 21.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-755: Improper Handling of Exceptional Conditions. EPSS 0.50%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 10, 2024 · Monitored products — high

    Detected

    An Improper Handling of Exceptional Conditions vulnerability in the Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an attacker sending a specific malformed BGP update message to cause the session to reset, resulting in a Denial of Service (DoS). Continued receipt and processing of these malformed BGP update messages will create a sustained Denial of Service

  2. Jun 17, 2026 · Monitored products — high

    Updated

    An Improper Handling of Exceptional Conditions vulnerability in the Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an attacker sending a specific malformed BGP update message to cause the session to reset, resulting in a Denial of Service (DoS). Continued receipt and processing of these malformed BGP update messages will create a sustained Denial of Service

Sources

  • CVE.orgVulnerability recordCVE-2024-39555

    Official CVE identifier

    cve.org
  • Monitored products — highVendor advisoryCVE-2024-39555

    An Improper Handling of Exceptional Conditions vulnerability in the Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an attacker sending a specific malformed BGP update message to cause the session to reset, resulting in a Denial of Service (DoS). Continued receipt and processing of these malformed BGP update messages will create a sustained Denial of Service

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 7, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgNov 7, 2026
  • Monitored products — highNov 7, 2026