How severe is CVE-2015-6279?

CVE-2015-6279 has a CVSS 2.0 base score of 7.8, rated high severity.

Is CVE-2015-6279 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-6279?

CVE-2015-6279 primarily affects Cisco Ios. In total, 139 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-6279?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2015-6279 published?

CVE-2015-6279 was published on 2015-09-28 and last updated on 2026-06-17.

CVE-2015-6279

CVE-2015-6279 is a high-severity vulnerability in Cisco Ios with a CVSS 2.0 base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 2.0 base score 7.8)
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Cisco Ios
Published: 2015-09-28
Last modified: 2026-06-17

Description

The IPv6 snooping functionality in the first-hop security subsystem in Cisco IOS 12.2, 15.0, 15.1, 15.2, 15.3, 15.4, and 15.5 and IOS XE 3.2SE, 3.3SE, 3.3XO, 3.4SG, 3.5E, and 3.6E before 3.6.3E; 3.7E before 3.7.2E; 3.9S and 3.10S before 3.10.6S; 3.11S before 3.11.4S; 3.12S and 3.13S before 3.13.3S; and 3.14S before 3.14.2S allows remote attackers to cause a denial of service (device reload) via a malformed ND packet with the Cryptographically Generated Address (CGA) option, aka Bug ID CSCuo04400.

Frequently asked questions

What is CVE-2015-6279?: The IPv6 snooping functionality in the first-hop security subsystem in Cisco IOS 12.2, 15.0, 15.1, 15.2, 15.3, 15.4, and 15.5 and IOS XE 3.2SE, 3.3SE, 3.3XO, 3.4SG, 3.5E, and 3.6E before 3.6.3E; 3.7E before 3.7.2E; 3.9S and 3.10S before 3.10.6S; 3.11S before 3.11.4S; 3.12S and 3.13S before 3.13.3S; and 3.14S before 3.14.2S allows remote attackers to cause a denial of service (device reload) via a malformed ND packet with the Cryptographically Generated Address (CGA) option, aka Bug ID CSCuo04400.
How severe is CVE-2015-6279?: CVE-2015-6279 has a CVSS 2.0 base score of 7.8, rated high severity.
Is CVE-2015-6279 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-6279?: CVE-2015-6279 primarily affects Cisco Ios. In total, 139 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-6279?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2015-6279 published?: CVE-2015-6279 was published on 2015-09-28 and last updated on 2026-06-17.

References

Affected products (139)

cpe:2.3:o:cisco:ios:12.2\(50\)sy:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.2\(50\)sy1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.2\(50\)sy2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.2\(50\)sy3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.2\(50\)sy4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)ex:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy6:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy7:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy7a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(1\)sy8:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)ea2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)ej:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)ej1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)ez:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se6:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se7:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2a\)ex5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(1\)sy:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(1\)sy1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(1\)sy2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(1\)sy3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(1\)sy4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(1\)sy5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(2\)sg:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(2\)sg1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(2\)sg2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(2\)sg3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(2\)sg4:*:*:*:*:*:*:*

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