CVE-2019-20894

mediumpriority · track · 31EPSS 0.016 · 75 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.56% (75th) EPSS

CVSS 4.3 · medium

Is it mine?

5 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

Traefik 2.x, in certain configurations, allows HTTPS sessions to proceed without mutual TLS verification in a situation where ERR_BAD_SSL_CLIENT_AUTH_CERT should have occurred.

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 · 4.3–7.5

v2.04.3mediumAV:N/AC:M/Au:N/C:P/I:N/A:Nprimary · NVD / NIST USexploitability 8.6 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · OSV

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-295USprimaryCWE-287USCWE-295US

affected products (5)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
traefik traefik2.0.0 → 2.0.1nvdUScpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*
Go github.com/containous/traefikall versionsosvUSpkg:golang/github.com/containous/traefik
Go github.com/containous/traefik/v2< 2.2.2osvUSpkg:golang/github.com/containous/traefik/v2
Go github.com/traefik/traefik/v2< 2.2.2osvUSpkg:golang/github.com/traefik/traefik/v2

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-q9mp-79cp-9g8jImproper Authentication2021-09-02ghsa · osvUS
Traefik 2.x, in certain configurations, allows HTTPS sessions to proceed without mutual TLS verification in a situation where ERR_BAD_SSL_CLIENT_AUTH_CERT should have occurred.
GO-2022-0774Improper Authentication in github.com/containous/traefik2024-08-21vendor · osvUS
Improper Authentication in github.com/containous/traefik

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2020-07-02modified 2026-06-17

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+1889 more

references (4)

External citations — patches, advisories, analysis.

https://github.com/containous/traefik/issues/5312 cnnvd
https://nvd.nist.gov/vuln/detail/CVE-2019-20894 cnnvd
https://github.com/containous/traefik/issues/5312 enisa_euvd
https://github.com/containous/traefik/issues/5312ExploitIssue TrackingThird Party Advisorynvd

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