CVE-2026-71190

openstack-swift: openstack-swift: Unauthenticated denial of service via catastrophic backtracking in Accept header parser

Published Aug 5, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4746-1 swift security update
History
Type Values Removed Values Added
Metrics ssvc

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

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

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Aug 6, 2026, 1:09 PM
Reserved
Aug 5, 2026, 4:54 AM
Status
Awaiting Analysis
Published
Aug 5, 2026, 6:16 AM
Modified
Oct 24, 2026, 3:10 PM
Severity
Moderate
Public date
Jul 28, 2026, 3:00 PM