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CVE-2019-16786

25
FAUCET Score

CVE-2019-16786 is a high-severity vulnerability affecting Waitress versions up to 1.3.1, as well as products from Debian, Fedora, Oracle, and Red Hat. It stems from improper parsing of the Transfer-Encoding header, allowing an attacker to bypass expected request body size determination. This could lead to HTTP request smuggling, where a single request is interpreted as multiple requests, potentially bypassing security controls. The vulnerability has a CVSS score of 7.5 (HIGH) due to its network attack vector, low attack complexity, and high impact on integrity, with no user interaction required. There is currently no evidence of active exploitation, public exploit code, or significant community discussion, and it is not listed in the CISA KEV catalog.

Impacted Technologies

VendorProductVersion(s)CPE
< 1.3.1CPE matchmatch criteria
cpe:2.3:a:agendaless:waitress:*:*:*:*:*:*:*:*
1.10.0CPE matchmatch criteria
cpe:2.3:a:oracle:communications_cloud_native_core_network_function_cloud_native_environment:1.10.0:*:*:*:*:*:*:*
9.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
30CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
31CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.1HIGH

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
LOW
Availability Impact
NONE
Exploitability Score
1.8
Impact Score
4.7
CvssVersion
3.1

Exploit Intelligence

EPSS Score
2.54%
Probability of exploitation in next 30 days
EPSS Percentile
83.4%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0255 is in the 70th percentile among its peer group of 51,553 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (19)

github_advisorypatch availablevia nvd_reference
View patch
oraclepatch availablevia nvd_reference
View patch
pippatch availablevia ghsa
Product: waitressFixed in: 1.4.0
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-bridge-operator-bundle:v3.4.0-3
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-bridge-operator-rhel8:v3.4.0-17
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-builder-qemu-rhcos-rhel8:v3.4.0-17
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-builder-rhel8:v3.4.0-18
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-container-security-operator-rhel8:v3.4.0-2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-openshift-bridge-rhel8-operator:v3.4.0-17
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-operator-bundle:v3.4.0-89
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-operator-rhel8:v3.4.0-132
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-rhel8:v3.4.0-51
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-container-security-operator-bundle:v3.4.0-2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat OpenStack Platform 15.0 (Stein)Fixed in: python-waitress-0:1.4.2-1.el8ost
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Quay 3Fixed in: quay/clair-rhel8:v3.4.0-25
View patch
redhatvendor investigatingvia redhat_api
Product: Red Hat Ceph Storage 3Fixed in: python-waitress
redhatvendor investigatingvia redhat_api
Product: Red Hat Ceph Storage 4Fixed in: python-waitress
redhatno patchvia redhat_api
Product: Red Hat OpenStack Platform 16 (Train)Fixed in: python-waitress
redhatend of lifevia redhat_api
Product: Red Hat OpenStack Platform 13 (Queens)Fixed in: python-waitress

Vendor Advisories (2)

pipGHSA-g2xc-35jw-c63pmedium

HTTP Request Smuggling: Invalid Transfer-Encoding in Waitress

Dec 20, 2019
redhatCVE-2019-16786Important

waitress: HTTP request smuggling through invalid Transfer-Encoding

Dec 20, 2019

References

access.redhat.com / errata/RHSA-2020:0720
Third Party Advisory
docs.pylonsproject.org / projects/waitress/en/latest
Release NotesVendor Advisory
github.com / Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3
PatchThird Party Advisory
github.com / Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p
Third Party Advisory
lists.debian.org / debian-lts-announce/2022/05/msg00011.html
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5
oracle.com / security-alerts/cpuapr2022.html
PatchThird Party Advisory