CVE-1999-1129

Cisco Catalyst 2900 Virtual LAN (VLAN) switches allow remote attackers to inject 802.1q frames into another VLAN by forging the VLAN identifier in the trunking tag.

Published: 1999-09-01 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-1999-1129 is rated Moderate Risk (56.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.60%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-1999-1129

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.87% 1.60% +0.73%
2 2025-03-17 0.55% 0.87% +0.33%
3 2024-12-17 — 0.55% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-1999-1129

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-1999-1129

Affected software / configurations for CVE-1999-1129

Vendor Product Version Raw CPE
cisco ios 11.2\(8\)sa5 cpe:2.3:o:cisco:ios:11.2\(8\)sa5:*:*:*:*:*:*:*
cisco catalyst_2900_vlan — cpe:2.3:h:cisco:catalyst_2900_vlan:*:*:*:*:*:*:*:*

References for CVE-1999-1129

cvelogic Threat Intelligence