In OpenStack Swift through 2.38.0, the proxy server Accept header parser contains a regular expression vulnerable to catastrophic backtracking (ReDoS). The "qdtext" pattern (?:[^"]|\\.)* allows an unauthenticated remote attacker to send a crafted Accept header that causes exponential CPU consumption in the proxy worker. A payload of 32 backslash-character pairs exceeds 30 seconds of CPU time. No authentication is required. Repeated requests can exhaust all proxy worker threads, resulting in a complete denial of service.
History

Thu, 06 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 06 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
Title OpenStack Swift Accept Header Regular Expression ReDoS Enables Denial of Service openstack-swift: openstack-swift: Unauthenticated denial of service via catastrophic backtracking in Accept header parser
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Wed, 05 Aug 2026 07:15:00 +0000

Type Values Removed Values Added
Title OpenStack Swift Accept Header Regular Expression ReDoS Enables Denial of Service

Wed, 05 Aug 2026 05:30:00 +0000

Type Values Removed Values Added
Description In OpenStack Swift through 2.38.0, the proxy server Accept header parser contains a regular expression vulnerable to catastrophic backtracking (ReDoS). The "qdtext" pattern (?:[^"]|\\.)* allows an unauthenticated remote attacker to send a crafted Accept header that causes exponential CPU consumption in the proxy worker. A payload of 32 backslash-character pairs exceeds 30 seconds of CPU time. No authentication is required. Repeated requests can exhaust all proxy worker threads, resulting in a complete denial of service.
First Time appeared Openstack
Openstack swift
Weaknesses CWE-1333
CPEs cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:*
Vendors & Products Openstack
Openstack swift
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-08-06T13:09:17.168Z

Reserved: 2026-08-05T04:54:02.394Z

Link: CVE-2026-71190

cve-icon Vulnrichment

Updated: 2026-08-05T18:32:08.027Z

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-28T15:00:00Z

Links: CVE-2026-71190 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-05T07:00:10Z