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Fencer Vulns
low 2.6

CVE-2006-4650 json

Cisco IOS 12.0, 12.1, and 12.2, when GRE IP tunneling is used and the RFC2784 compliance fixes are missing, does not verify the offset fiel…

published 2006-09-09 20 y ago modified 2026-06-16 4 mo ago also EUVD-2006-4638

cvss
2.6
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.2%
EPSS 3.2% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

Cisco IOS 12.0, 12.1, and 12.2, when GRE IP tunneling is used and the RFC2784 compliance fixes are missing, does not verify the offset field of a GRE packet during decapsulation, which leads to an integer overflow that references data from incorrect memory locations, which allows remote attackers to inject crafted packets into the routing queue, possibly bypassing intended router ACLs.

Exploit prediction

3.23% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 2.6 AV:N/AC:H/Au:N/C:P/I:N/A:N

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.