OpenStack Swift up to 2.35.3/2.36.2/2.37.2/2.38.0 Accept Header Parser redos

Summaryinfo

A vulnerability marked as critical has been reported in OpenStack Swift up to 2.35.3/2.36.2/2.37.2/2.38.0. The impacted element is an unknown function of the component Accept Header Parser. Performing a manipulation results in redos. This vulnerability is cataloged as CVE-2026-71190. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as critical has been found in OpenStack Swift up to 2.35.3/2.36.2/2.37.2/2.38.0. This affects an unknown code of the component Accept Header Parser. The manipulation with an unknown input leads to a redos vulnerability. CWE is classifying the issue as CWE-1333. The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles. This is going to have an impact on availability. The summary by CVE is:

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.

It is possible to read the advisory at launchpad.net. This vulnerability is uniquely identified as CVE-2026-71190 since 08/05/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1449.003 according to MITRE ATT&CK.

Upgrading to version 2.35.4, 2.36.3 or 2.37.3 eliminates this vulnerability.

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Productinfo

Type

• Cloud Software

Vendor

• OpenStack

Name

• Swift

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16
• 2.17
• 2.18
• 2.19
• 2.20
• 2.21
• 2.22
• 2.23
• 2.24
• 2.25
• 2.26
• 2.27
• 2.28
• 2.29
• 2.30
• 2.31
• 2.32
• 2.33
• 2.34
• 2.35
• 2.35.0
• 2.35.1
• 2.35.2
• 2.35.3
• 2.36
• 2.36.0
• 2.36.1
• 2.36.2
• 2.37
• 2.37.0
• 2.37.1
• 2.37.2
• 2.38.0

License

• free

Website

• Vendor: https://www.openstack.org/

CPE 2.3info

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CPE 2.2info

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