What is CVE-2019-1849?

CVE-2019-1849 is a high-severity vulnerability in Cisco iOS Xr Software, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 7.4/10. Published 2019-05-16.

How severe is CVE-2019-1849?

High severity. CVSS v3 base score is 7.4 out of 10.

Vulnerability in Cisco iOS Xr Software

CVE-2019-1849

A vulnerability in the Border Gateway Patrol (BGP) Multiprotocol Label Switching (MPLS)-based Ethernet VPN (EVPN) implementation of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to trigger a denial of service (DoS) condition on an affected device. The vulnerability is due to a logic error that occurs when the affected software processes specific EVPN routing information. An attacker could exploit this vulnerability by injecting malicious traffic patterns into the targeted EVPN network. A successful exploit could result in a crash of the l2vpn_mgr process on Provider Edge (PE) device members of the same EVPN instance (EVI). On each of the affected devices, a crash could lead to system instability and the inability to process or forward traffic through the device, resulting in a DoS condition that would require manual intervention to restore normal operating conditions.

Published 2019-05-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (49.0th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Cisco iOS Xr Software — versions unspecified
Cisco iOS Xr

Weakness classification (CWE)

CWE-754 — Improper Check for Unusual or Exceptional Conditions

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515… (vendor-advisory, Vendor Advisory)
www.securityfocus.com/bid/108342 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2019-1849?: CVE-2019-1849 is a high-severity vulnerability in Cisco iOS Xr Software, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 7.4/10. Published 2019-05-16.
How severe is CVE-2019-1849?: High severity. CVSS v3 base score is 7.4 out of 10.