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Fencer Intel
high 8.6

CVE-2019-1886 json

Cisco Web Security Appliance HTTPS Certificate Denial of Service Vulnerability

published 7y ago modified 4mo ago also EUVD-2019-10443

cvss
8.6
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 71%
public exploits
0
none known

Summary

A vulnerability in the HTTPS decryption feature of Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient validation of Secure Sockets Layer (SSL) server certificates. An attacker could exploit this vulnerability by installing a malformed certificate in a web server and sending a request to it through the Cisco WSA. A successful exploit could allow the attacker to cause an unexpected restart of the proxy process on an affected device.

Patch / fix

  • Cisco Cisco Web Security Appliance (WSA) 10.5.5-005

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last yr.

Exploit prediction

1.35% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 8.6 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • Cisco Cisco Web Security Appliance (WSA)

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-295 Improper Certificate Validation

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.