How severe is CVE-2006-6265?

CVE-2006-6265 has a CVSS 2.0 base score of 5.8, rated medium severity.

Is CVE-2006-6265 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2006-6265?

CVE-2006-6265 affects Microsoft Teredo. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2006-6265?

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

When was CVE-2006-6265 published?

CVE-2006-6265 was published on 2006-12-04 and last updated on 2026-06-16.

CVE-2006-6265

CVE-2006-6265 is a medium-severity vulnerability in Microsoft Teredo with a CVSS 2.0 base score of 5.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 2.0 base score 5.8)
EPSS exploit prediction: 4% (90th 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 located behind a restricted NAT, allow remote attackers to establish an inbound connection without the guessing required to find a port mapping for a traditional restricted NAT client, by (1) using the client port number contained in the Teredo address or (2) following the bubble-to-open procedure.

Frequently asked questions

What is CVE-2006-6265?: Teredo clients, when located behind a restricted NAT, allow remote attackers to establish an inbound connection without the guessing required to find a port mapping for a traditional restricted NAT client, by (1) using the client port number contained in the Teredo address or (2) following the bubble-to-open procedure.
How severe is CVE-2006-6265?: CVE-2006-6265 has a CVSS 2.0 base score of 5.8, rated medium severity.
Is CVE-2006-6265 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2006-6265?: CVE-2006-6265 affects Microsoft Teredo. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2006-6265?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2006-6265 published?: CVE-2006-6265 was published on 2006-12-04 and last updated on 2026-06-16.

References

Affected products (1)

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

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CVE-2006-6266 — Medium (CVSS 6.8): Teredo clients, when following item 6 of RFC4380 section 5.2.3, start direct IPv6 connectivity tests (aka ping tests)…
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…

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