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Fencer Vulns
high 7.5

CVE-1999-1306 json

Cisco IOS 9.1 and earlier does not properly handle extended IP access lists when the IP route cache is enabled and the "established" keywor…

published 1992-12-10 33 y ago modified 2026-06-16 4 mo ago also EUVD-1999-1287

cvss
7.5
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 72%
public exploits
0
none known

Summary

Cisco IOS 9.1 and earlier does not properly handle extended IP access lists when the IP route cache is enabled and the "established" keyword is set, which could allow attackers to bypass filters.

Patch / fix

Exploit prediction

1.39% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

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.