Vulnerabilities in pkg:pypi/waitress

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Advisory Summary

GHSA-j7j6-7hfx-5522 is a HIGH (CVSS 7.5) inconsistent interpretation of http requests vulnerability (CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')) affecting Duplicate Advisory libraries in the PyPI ecosystem. The issue involves inconsistent interpretation of http requests in waitress. Remediation is available by upgrading affected packages to version 1.4.0.

11 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:pypi/waitress

11 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:pypi/waitress. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-j7j6-7hfx-5522 - HIGH Duplicate Advisory: Inconsistent Interpretation of HTTP Requests in Waitress
GHSA-4ppp-gpcr-7qf6 CVE-2019-16792 CRITICAL HTTP Request Smuggling: Content-Length Sent Twice in Waitress
GHSA-3f84-rpwh-47g6 CVE-2024-49769 HIGH Waitress vulnerable to DoS leading to high CPU usage/resource exhaustion
GHSA-9298-4cf8-g4wj CVE-2024-49768 CRITICAL Waitress has request processing race condition in HTTP pipelining with invalid first request
GHSA-f5x9-8jwc-25rw CVE-2022-31015 HIGH Uncaught Exception (due to a data race) leads to process termination in Waitress
GHSA-4f7p-27jc-3c36 CVE-2022-24761 HIGH HTTP Request Smuggling in waitress
GHSA-73m2-3pwg-5fgc CVE-2020-5236 MODERATE Catastrophic backtracking in regex allows Denial of Service in Waitress
GHSA-968f-66r5-5v74 CVE-2019-16789 MODERATE HTTP Request Smuggling in Waitress: Invalid whitespace characters in headers (Follow-up)
GHSA-g2xc-35jw-c63p CVE-2019-16786 MODERATE HTTP Request Smuggling: Invalid Transfer-Encoding in Waitress
GHSA-pg36-wpm5-g57p CVE-2019-16785 MODERATE HTTP Request Smuggling: LF vs CRLF handling in Waitress
GHSA-m5ff-3wj3-8ph4 - HIGH HTTP Request Smuggling: Invalid whitespace characters in headers in Waitress

GHSA-j7j6-7hfx-5522 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-j7j6-7hfx-5522
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Affected Product Duplicate Advisory
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix GHSA-j7j6-7hfx-5522

To remediate this vulnerability, upgrade all affected Duplicate Advisory dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

waitress fixed: 1.4.0 
pip install waitress>=1.4.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show waitress

How to Check if You Are Affected

To determine whether your Python environment is affected by GHSA-j7j6-7hfx-5522, inspect your installed packages using pip:

pip show waitress

Analyze the terminal output to locate any version of Duplicate Advisory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.0), your application is affected.

Note: The pip show waitress command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'), where the product acts as an intermediary http agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed http requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. In Duplicate Advisory, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-4ppp-gpcr-7qf6. This link is maintained to preserve external references. ## Original Description Waitress through version 1.3.1 allows request smuggling by sending the Content-Length header twice. Waitress would header fold a double Content-Length header and due to being unable to cast the now comma separated value to an integer would set the Content-Length to 0 internally. If two Content-Length headers are sent in a single request, Waitress would treat the request as having no body, thereby treating the body of the request as a new request in HTTP pipelining. This issue is fixed in Waitress 1.4.0.

GHSA-j7j6-7hfx-5522 Affected Duplicate Advisory Versions

1 component(s)
Fixed Versions:
1.4.0
Product / Package Ecosystem Affected Versions Fixed Version
waitress
pypi/waitress
PyPI
< 1.4.0
1.4.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/Pylons/waitress/security/advisories/GHSA-4ppp-gpcr-7qf6
NVD — GHSA-j7j6-7hfx-5522 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-16792
Security Fix Commit FIX COMMIT
https://github.com/Pylons/waitress/commit/575994cd42e83fd772a5f7ec98b2c56751bd3f65
docs.pylonsproject.org/projects/waitress/e... WEB
https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes
Duplicate Advisory Source Repository REPOSITORY
https://github.com/Pylons/waitress
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html
Duplicate Advisory Security Information SECURITY
https://www.oracle.com/security-alerts/cpuapr2022.html

Frequently Asked Questions

What is GHSA-j7j6-7hfx-5522?
GHSA-j7j6-7hfx-5522 is a security vulnerability in Duplicate Advisory involving Inconsistent Interpretation of HTTP Requests in Waitress under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling').
Which Duplicate Advisory versions are affected?
Affected versions include releases prior to 1.4.0 across affected packages: waitress.
What version fixes GHSA-j7j6-7hfx-5522?
Upgrading to 1.4.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is waitress affected?
Yes, waitress is affected in releases prior to 1.4.0. Upgrade your dependency to 1.4.0 or later.
What is the CVSS score of GHSA-j7j6-7hfx-5522?
GHSA-j7j6-7hfx-5522 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with GHSA-j7j6-7hfx-5522?
GHSA-j7j6-7hfx-5522 is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') (The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.).
How can I check PyPI dependencies for GHSA-j7j6-7hfx-5522?
Run the dependency tree command: 'pip show waitress'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-j7j6-7hfx-5522",
  "modified" : "2026-02-25T14:07:30Z",
  "published" : "2022-05-24T17:07:06Z",
  "withdrawn" : "2026-01-22T22:34:03Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: Inconsistent Interpretation of HTTP Requests in Waitress",
  "details" : "## Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-4ppp-gpcr-7qf6. This link is maintained to preserve external references.\n\n## Original Description\nWaitress through version 1.3.1 allows request smuggling by sending the Content-Length header twice. Waitress would header fold a double Content-Length header and due to being unable to cast the now comma separated value to an integer would set the Content-Length to 0 internally. If two Content-Length headers are sent in a single request, Waitress would treat the request as having no body, thereby treating the body of the request as a new request in HTTP pipelining. This issue is fixed in Waitress 1.4.0.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "waitress"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.3.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Pylons/waitress/security/advisories/GHSA-4ppp-gpcr-7qf6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-16792"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Pylons/waitress/commit/575994cd42e83fd772a5f7ec98b2c56751bd3f65"
  }, {
    "type" : "WEB",
    "url" : "https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Pylons/waitress"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuapr2022.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-444" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-27T16:10:41Z",
    "nvd_published_at" : "2020-01-22T19:15:00Z"
  }
}