Vulnerabilities

Vulnerability · CVE-2016-4921

By flooding a Juniper Networks router running Junos OS with specially crafted IPv6 traffic, all available resources can be consumed, leading to the inability to store…

Published Oct 13, 2017 · catalog updated Jun 17, 2026 · the affected product

Last checked Nov 10, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2016-4921. EPSS is 2.91%. 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
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
2.91%
Remediation
Advisory link
Affected products
cpe juniper/junos

By flooding a Juniper Networks router running Junos OS with specially crafted IPv6 traffic, all available resources can be consumed, leading to the inability to store next hop information for legitimate traffic. In extreme cases, the crafted IPv6 traffic may result in a total resource exhaustion and kernel panic. The issue is triggered by traffic destined to the router. Transit traffic does not trigger the vulnerability. This issue only affects devices with IPv6 enabled and configured. Devices not configured to process IPv6 traffic are unaffected by this vulnerability. This issue was found during internal product security testing. Juniper SIRT is not aware of any malicious exploitation of this vulnerability. Affected releases are Juniper Networks Junos OS 11.4 prior to 11.4R13-S3; 12.3 prior to 12.3R3-S4; 12.3X48 prior to 12.3X48-D30; 13.3 prior to 13.3R10, 13.3R4-S11; 14.1 prior to 14.1R2-S8, 14.1R4-S12, 14.1R8; 14.1X53 prior to 14.1X53-D28, 14.1X53-D40; 14.1X55 prior to 14.1X55-D35; 14.2 prior to 14.2R3-S10, 14.2R4-S7, 14.2R6; 15.1 prior to 15.1F2-S5, 15.1F5-S2, 15.1F6, 15.1R3; 15.1X49 prior to 15.1X49-D40; 15.1X53 prior to 15.1X53-D57, 15.1X53-D70.

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/junos11.4

How to fix CVE-2016-4921

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-2016-4921. EPSS is 2.91%. Act only if a listed version of the affected product is installed.

Which versions are affected?

Compare what you have installed with 11.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-399. EPSS 2.91%. 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. Oct 13, 2017 · Monitored products — high

    Detected

    By flooding a Juniper Networks router running Junos OS with specially crafted IPv6 traffic, all available resources can be consumed, leading to the inability to store next hop information for legitimate traffic. In extreme cases, the crafted IPv6 traffic may result in a total resource exhaustion and kernel panic. The issue is triggered by traffic destined to the router. Transit traffic does not tr

  2. Jun 17, 2026 · Monitored products — high

    Updated

    By flooding a Juniper Networks router running Junos OS with specially crafted IPv6 traffic, all available resources can be consumed, leading to the inability to store next hop information for legitimate traffic. In extreme cases, the crafted IPv6 traffic may result in a total resource exhaustion and kernel panic. The issue is triggered by traffic destined to the router. Transit traffic does not tr

Sources

  • CVE.orgVulnerability recordCVE-2016-4921

    Official CVE identifier

    cve.org
  • Monitored products — highVendor advisoryCVE-2016-4921

    By flooding a Juniper Networks router running Junos OS with specially crafted IPv6 traffic, all available resources can be consumed, leading to the inability to store next hop information for legitimate traffic. In extreme cases, the crafted IPv6 traffic may result in a total resource exhaustion and kernel panic. The issue is triggered by traffic destined to the router. Transit traffic does not tr

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 10, 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