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TI-2024-33235 Aliases CVE-2024-49768GHSA-9298-4cf8-g4wj

Waitress has request processing race condition in HTTP pipelining with invalid first request

Priority MEDIUM 48CWE-367Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · None
Fix status
Partial Red Hat: 8 fixed, 3 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

Waitress is a Web Server Gateway Interface server for Python 2 and 3. A remote client may send a request that is exactly recv_bytes (defaults to 8192) long, followed by a secondary request using HTTP pipelining. When request lookahead is disabled (default) we won't read any more requests, and when the first request fails due to a parsing error, we simply close the connection. However when request lookahead is enabled, it is possible to process and receive the first request, start sending the error message back to the client while we read the next request and queue it. This will allow the secondary request to be serviced by the worker thread while the connection should be closed. Waitress 3.0.1 fixes the race condition. As a workaround, disable channel_request_lookahead, this is set to 0 by default disabling this feature.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00486 42nd percentileScored 2026-11-07
Fix Partial waitress (Pylons): 3.0.1waitress (PyPI): 3.0.1Red Hat: 9 advisoriesRed Hat: 8 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Pylonswaitress2.0.0 to before 3.0.13.0.1Patch availableCNA
—waitress (PyPI)2.0.0 to before 3.0.13.0.1Patch availableGHSA-9298-4cf8-g4wj
  • waitress VendorPylons Affected 2.0.0 to before 3.0.1 Fixed in 3.0.1 Patch available CNA
  • waitress (PyPI) Vendor— Affected 2.0.0 to before 3.0.1 Fixed in 3.0.1 Patch available GHSA-9298-4cf8-g4wj

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:agendaless:waitress:*:*:*:*:*:*:*:*2.0.0 to before 3.0.1VulnerableAgendaless
  • cpe:2.3:a:agendaless:waitress:*:*:*:*:*:*:*:* Versions 2.0.0 to before 3.0.1 Vulnerable ·Agendaless

Remediation

  • Fix · CNA waitress (Pylons) Fixed in 3.0.1
  • Fix · GHSA-9298-4cf8-g4wj waitress (PyPI) Fixed in 3.0.1 Advisory →

Red Hat 9 advisories

  • RHSA-2025:1192 Released 2025-02-10 · Red Hat rating Important
    Red Hat OpenStack Platform 17.1 (python-waitress) security update
    • Red Hat OpenStack Platform 17.1 python-waitress-2.0.0-4.el8ost, python3-waitress-2.0.0-4.el8ost
  • RHSA-2025:1191 Released 2025-02-10 · Red Hat rating Important
    Red Hat OpenStack Platform 17.1 (python-waitress) security update
    • Red Hat OpenStack Platform 17.1 python-waitress-2.0.0-4.el9ost, python3-waitress-2.0.0-4.el9ost
  • RHSA-2025:0201 Released 2025-01-09 · Red Hat rating Important
    Red Hat OpenStack Platform 16.2 (python-waitress) security update
    • Red Hat OpenStack Platform 16.2 python-waitress-2.0.0-4.el8ost, python3-waitress-2.0.0-4.el8ost
Show 6 more Red Hat advisories
  • RHSA-2024:10815 Released 2024-12-12 · Red Hat rating Important
    OpenShift Container Platform 4.13.54 packages and security update
    • Ironic content for Red Hat OpenShift Container Platform 4.13 python-waitress-3.0.1-1.el9, python3-waitress-3.0.1-1.el9
  • RHSA-2024:10535 Released 2024-12-05 · Red Hat rating Important
    OpenShift Container Platform 4.12.70 security update
    • Ironic content for Red Hat OpenShift Container Platform 4.12 python-waitress-3.0.1-1.el9, python3-waitress-3.0.1-1.el9
  • RHSA-2024:10145 Released 2024-11-26 · Red Hat rating Important
    OpenShift Container Platform 4.15.39 packages and security update
    • Ironic content for Red Hat OpenShift Container Platform 4.15 python-waitress-3.0.1-1.el9, python3-waitress-3.0.1-1.el9
  • RHSA-2024:9623 Released 2024-11-20 · Red Hat rating Important
    OpenShift Container Platform 4.14.41 packages and security update
    • Ironic content for Red Hat OpenShift Container Platform 4.14 python-waitress-3.0.1-1.el9, python3-waitress-3.0.1-1.el9
  • RHSA-2024:9618 Released 2024-11-20 · Red Hat rating Important
    OpenShift Container Platform 4.16.23 packages and security update
    • Ironic content for Red Hat OpenShift Container Platform 4.16 python-waitress-3.0.1-1.el9, python3-waitress-3.0.1-1.el9
  • RHSA-2024:9613 Released 2024-11-19 · Red Hat rating Important
    OpenShift Container Platform 4.17.5 security update
    • Ironic content for Red Hat OpenShift Container Platform 4.17 python-waitress-3.0.1-1.el9, python3-waitress-3.0.1-1.el9

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Ceph Storage 4AffectedNo fix planned: Out of support scope
Red Hat Ceph Storage 5AffectedNo fix yet
Red Hat Openshift Container Storage 4AffectedNo fix yet
Ironic content for Red Hat OpenShift Container Platform 4.12Fixed RHSA-2024:10535
Ironic content for Red Hat OpenShift Container Platform 4.13Fixed RHSA-2024:10815
Ironic content for Red Hat OpenShift Container Platform 4.14Fixed RHSA-2024:9623
Ironic content for Red Hat OpenShift Container Platform 4.15Fixed RHSA-2024:10145
Ironic content for Red Hat OpenShift Container Platform 4.16Fixed RHSA-2024:9618
Ironic content for Red Hat OpenShift Container Platform 4.17Fixed RHSA-2024:9613
Red Hat OpenStack Platform 16.2Fixed RHSA-2025:0201
Red Hat OpenStack Platform 17.1Fixed RHSA-2025:1191, RHSA-2025:1192
Not affected: 5 products
  • Red Hat OpenShift Container Platform 4.12
  • Red Hat OpenShift Container Platform 4.13
  • Red Hat OpenShift Container Platform 4.14
  • Red Hat OpenShift Container Platform 4.16
  • Red Hat OpenShift Container Platform 4.17

Timeline

  1. 2026-10-02 Threatist record created from CVE-2024-49768
  2. 2026-10-03 Alias added: GHSA-9298-4cf8-g4wj

References

Patch 1

Advisory 2

Other 2

  • TI-2022-13060 Uncaught Exception (due to a data race) leads to process termination in Waitress CVSS 3.1MEDIUM 6.5
  • TI-2026-39576 WebOb: Open redirect in Location header normalization via leading C0 control / space characters CVSS 3.1MEDIUM 6.1
  • TI-2024-33236 Waitress has a denial of service leading to high CPU usage/resource exhaustion CVSS 3.1HIGH 7.5
  • TI-2022-08575 HTTP Request Smuggling in waitress CVSS 3.1HIGH 7.5
  • TI-2019-12566 HTTP Request Smuggling in Waitress: Invalid whitespace characters in headers CVSS 3.1HIGH 8.2
  • TI-2019-12564 HTTP Request Smuggling: LF vs CRLF handling in Waitress CVSS 3.1HIGH 7.5
See all 14 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences