How severe is CVE-2006-6266?

CVE-2006-6266 has a CVSS 2.0 base score of 6.8, rated medium severity.

Is CVE-2006-6266 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 12% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2006-6266?

CVE-2006-6266 affects Microsoft Teredo. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2006-6266?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2006-6266 published?

CVE-2006-6266 was published on 2006-12-04 and last updated on 2026-06-16.

CVE-2006-6266

CVE-2006-6266 is a medium-severity vulnerability in Microsoft Teredo with a CVSS 2.0 base score of 6.8. Its EPSS exploit-prediction score of 12% places it in the 96th percentile, indicating an elevated likelihood of exploitation.

Key facts

Severity: Medium (CVSS 2.0 base score 6.8)
EPSS exploit prediction: 12% (96th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Teredo
Published: 2006-12-04
Last modified: 2026-06-16

Description

Teredo clients, when following item 6 of RFC4380 section 5.2.3, start direct IPv6 connectivity tests (aka ping tests) in response to packets from non-Teredo source addresses, which might allow remote attackers to induce Teredo clients to send packets to third parties.

Frequently asked questions

What is CVE-2006-6266?: Teredo clients, when following item 6 of RFC4380 section 5.2.3, start direct IPv6 connectivity tests (aka ping tests) in response to packets from non-Teredo source addresses, which might allow remote attackers to induce Teredo clients to send packets to third parties.
How severe is CVE-2006-6266?: CVE-2006-6266 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2006-6266 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 12% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2006-6266?: CVE-2006-6266 affects Microsoft Teredo. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2006-6266?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2006-6266 published?: CVE-2006-6266 was published on 2006-12-04 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:microsoft:teredo:*:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Teredo

CVE-2006-6264 — High (CVSS 7.5): Teredo creates trusted peer entries for arbitrary incoming source Teredo addresses, even if the low 32 bits represent…
CVE-2006-6263 — Medium (CVSS 6.8): Teredo clients, when source routing is enabled, recognize a Routing header in an encapsulated IPv6 packet and send the…
CVE-2006-6265 — Medium (CVSS 5.8): Teredo clients, when located behind a restricted NAT, allow remote attackers to establish an inbound connection without…

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