CVE-2019-12656

mediumpriority · track · 31EPSS 0.018 · 79 %ileEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.82% (79th) EPSS
CVSS 5 · medium
Is it mine?
29 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the IOx application environment of multiple Cisco platforms could allow an unauthenticated, remote attacker to cause the IOx web server to stop processing HTTPS requests, resulting in a denial of service (DoS) condition. The vulnerability is due to a Transport Layer Security (TLS) implementation issue. An attacker could exploit this vulnerability by sending crafted TLS packets to the IOx web server on an affected device. A successful exploit could allow the attacker to cause the IOx web server to stop processing HTTPS requests, resulting in a DoS condition.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6
v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU
v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 3.6
v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · Cisco PSIRT US
v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USCWE-20US
05

affected products (29)

Products and version ranges known to be affected.

showing 20 of 29
06

advisories (1)

Vendor and ecosystem advisories describing this.

  • cisco-sa-20190925-ioxCisco IOx Application Environment Denial of Service Vulnerability2019-09-25csaf · cisco_csafUS

    A vulnerability in the IOx application environment of multiple Cisco platforms could allow an unauthenticated, remote attacker to cause the IOx web server to stop processing HTTPS requests, resulting in a denial of service (DoS) condition. The vulnerability is due to a Transport Layer Security (TLS) implementation issue. An attacker could exploit this vulnerability by sending crafted TLS packets to the IOx web server on an affected device. A successful exploit could allow the attacker to cause the IOx web server to stop processing HTTPS requests, resulting in a DoS condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the September 25, 2019, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 12 Cisco Security Advisories that describe 13 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: September 2019 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-72547"].

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisco_csafNVDCVE.orgMITRE
published 2019-09-25modified 2026-06-17
09

references (7)

External citations — patches, advisories, analysis.

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