CVE-2018-0063
Junos OS: Nexthop index allocation failed: private index space exhausted after incoming ARP requests to management interface
- 6.5MediumCVSS base score
- 0.64%Exploitation in 30 daysEPSS · top 49% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A vulnerability in the IP next-hop index database in Junos OS 17.3R3 may allow a flood of ARP requests, sent to the management interface, to exhaust the private Internal routing interfaces (IRIs) next-hop limit. Once the IRI next-hop database is full, no further next hops can be learned and existing entries cannot be cleared, leading to a sustained denial of service (DoS) condition. An indicator of compromise for this issue is the report of the following error message: %KERN-4: Nexthop index allocation failed: private index space exhausted This issue only affects the management interface, and does not impact regular transit traffic through the FPCs. This issue also only affects Junos OS 17.3R3. No prior versions of Junos OS are affected by this issue. Affected releases are Juniper Networks Junos OS: 17.3R3.
Timeline
ID reserved
By juniper
- 11 months later
· 11 months later
Published
- 6 years later
· 6 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| juniperCNA (assigner) | 3.0 | Medium6.5 | CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.64% · top 49% of all CVEs (9 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Affected products
- affected 17.3R3 – < 17.3R3-S1
What to do
Solution: The following software releases have been updated to recover from private index space exhaustion: 17.3R3-S1 and all subsequent releases.
Workaround: There are no viable workarounds for this issue.
Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
References
2
- 1041861 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- https://kb.juniper.net/JSA10899 (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2018-0887 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2018-0063)Record last updated .