Vulnerability in Cisco IOS 11.1CC and 11.1CT with distributed fast switching (DFS) enabled allows remote attackers to bypass certain access…

published 1999-12-31 26y ago modified 2026-06-16 4mo ago also EUVD-1999-1445

cvss: 7.5; version 2.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.6%; EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits: 0; none known

Vulnerability in Cisco IOS 11.1CC and 11.1CT with distributed fast switching (DFS) enabled allows remote attackers to bypass certain access control lists when the router switches traffic from a DFS-enabled interface to an interface that does not have DFS enabled, as described by Cisco bug CSCdk35564.

Patch / fix

links 2

cisco.com/warp/public/770/iosdfsacl-pub.shtml advisory
ciac.llnl.gov/ciac/bulletins/j-016.shtml advisory

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Exploit prediction

1.63% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-14).

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

Cisco IOS rss critical rss

References

cisco.com /warp/public/770/iosdfsacl-pub.shtml
vendor-advisory, patch
ciac.llnl.gov /ciac/bulletins/j-016.shtml
third-party-advisory, government-resource, patch, vendor-advisory
exchange.xforce.ibmcloud.com /vulnerabilities/1401
vdb-entry

Sources

CVE List CVE-1999-1464
NVD CVE-1999-1464

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