How severe is CVE-2006-6263?

CVE-2006-6263 has a CVSS 2.0 base score of 6.8, rated medium severity.

Is CVE-2006-6263 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-2006-6263?

CVE-2006-6263 affects Microsoft Teredo. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2006-6263?

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

When was CVE-2006-6263 published?

CVE-2006-6263 was published on 2006-12-04 and last updated on 2026-06-16.

CVE-2006-6263

CVE-2006-6263 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 source routing is enabled, recognize a Routing header in an encapsulated IPv6 packet and send the packet to the next hop, which might allow remote attackers to bypass policies of certain Internet gateways that drop all source-routed packets.

Frequently asked questions

What is CVE-2006-6263?: Teredo clients, when source routing is enabled, recognize a Routing header in an encapsulated IPv6 packet and send the packet to the next hop, which might allow remote attackers to bypass policies of certain Internet gateways that drop all source-routed packets.
How severe is CVE-2006-6263?: CVE-2006-6263 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2006-6263 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-2006-6263?: CVE-2006-6263 affects Microsoft Teredo. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2006-6263?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2006-6263 published?: CVE-2006-6263 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-2006-6264 — High (CVSS 7.5): Teredo creates trusted peer entries for arbitrary incoming source Teredo addresses, even if the low 32 bits represent…
CVE-2006-6266 — 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-2006-6265 — 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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