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CVE-2015-4199
Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing Engine (PRE) module on UBR devices allows…
- 7.1HighCVSS base score
- 2.1%Exploitation in 30 daysEPSS · top 18% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing Engine (PRE) module on UBR devices allows remote attackers to cause a denial of service (NULL pointer free and module crash) by triggering intermittent connectivity with many IPv6 CPE devices, aka Bug ID CSCug47366.
Timeline
ID reserved
By cisco
- 23 days later
· 23 days later
Published
- 9 years later
· 9 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 |
|---|---|---|---|
| NVDNVD · Modified | 2.0 | High7.1 | AV:N/AC:M/Au:N/C:N/I:N/A:C |
- EPSS (exploitation in 30 days)
- 2.1% · top 18% of all CVEs (9 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Affected products
n/a
- affected n/a
References
3
- 1032692 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- 20150622 Cisco IOS Software UBR Devices IPv6 to IPv4 Subsystem Denial of Service Vulnerability (opens in a new tab)vendor-advisoryx_refsource_CISCOx_transferred
- 75335 (opens in a new tab)vdb-entryx_refsource_BIDx_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-2015-4222 (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-2015-4199)Record last updated .