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Fencer Intel
high 7.4

CVE-2019-1910 json

Cisco IOS XR Software Intermediate System to Intermediate System Denial of Service Vulnerability

published 7y ago modified 4mo ago also EUVD-2019-10467

cvss
7.4
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

A vulnerability in the implementation of the Intermediate System–to–Intermediate System (IS–IS) routing protocol functionality in Cisco IOS XR Software could allow an unauthenticated attacker who is in the same IS–IS area to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of crafted IS–IS link-state protocol data units (PDUs). An attacker could exploit this vulnerability by sending a crafted link-state PDU to an affected system to be processed. A successful exploit could allow the attacker to cause all routers within the IS–IS area to unexpectedly restart the IS–IS process, resulting in a DoS condition. This vulnerability affects Cisco devices if they are running a vulnerable release of Cisco IOS XR Software earlier than Release 6.6.3 and are configured with the IS–IS routing protocol. Cisco has confirmed that this vulnerability affects both Cisco IOS XR 32-bit Software and Cisco IOS XR 64-bit Software.

Patch / fix

  • Cisco Cisco IOS XR Software 6.6.3

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 7.4 CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 3.1 7.4 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 2.0 6.1 AV:A/AC:L/Au:N/C:N/I:N/A:C

Affected products

  • Cisco Cisco IOS XR Software

Classification

Weakness
  • CWE-20 Improper Input Validation
Technology feeds

References

Sources

Fencer Intel 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.