CVE-2026-71190

Enriched by CISA
 

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.
https://nvd.nist.gov/vuln/detail/CVE-2026-71190

Categories

CWE-1333 : Inefficient Regular Expression Complexity
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. ReDoS is an abbreviation of "Regular expression Denial of Service". While this term is attack-focused, this is commonly used to describe the weakness. This term is used to describe the behavior of the regular expression as a negative technical impact. Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) Use regular expressions that do not support backtracking, e.g. by removing nested quantifiers. Set backtracking limits in the configuration of the regular expression implementation, such as PHP's pcre.backtrack_limit. Also consider limits on execution time for the process. Do not use regular expressions with untrusted input. If regular expressions must be used, avoid using backtracking in the expression. Limit the length of the input that the regular expression will process. server allows ReDOS with crafted User-Agent strings, due to overlapping capture groups that cause excessive backtracking. npm package for user-agent parser prone to ReDoS due to overlapping capture groups Markdown parser uses inefficient regex when processing a message, allowing users to cause CPU consumption and delay preventing processing of other messages. Long string in a version control product allows DoS due to an inefficient regex. Javascript code allows ReDoS via a long string due to excessive backtracking. ReDoS when parsing time. ReDoS when parsing documents. ReDoS when validating URL.

References


 

AFFECTED (from MITRE)

Vendor Product Versions
OpenStack Swift
  • 1.9.1 < 2.35.4 [affected]
  • 2.36.0 < 2.36.3 [affected]
  • 2.37.0 < 2.37.3 [affected]
  • 2.38.0 [affected]
© 2022 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.

CPE

cpe start end
Configuration 1
cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:* >= 1.9.1 < 2.35.4
cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:* >= 2.36.0 < 2.36.3
cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:* >= 2.37.0 < 2.37.3
cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:* >= 2.38.0 <= 2.38.0

REMEDIATION


EXPLOITS

Exploit-db.com

id description date
No known exploits

POC Github

Url
No known exploits

Other Nist (github, ...)

Url
No known exploits

CAPEC

Common Attack Pattern Enumerations and Classifications

id description severity
492 Regular Expression Exponential Blowup