CVE-2026-71190Network attack vectorHinoki check available

Proxy service interruption via Accept header backtracking

Published Aug 5, 2026 · Updated Aug 5, 2026

Regular expression denial of service in OpenStack Swift allows remote attackers to interrupt proxy service via a crafted Accept header. The listing_formats middleware applies the qdtext pattern to an unterminated quoted value, and overlapping repeatable alternatives for backslashes trigger catastrophic backtracking in a proxy worker. Authentication is not required because the header is parsed before authentication; repeated requests consume the worker pool and make object storage unavailable.

CVSS severity7.5
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Regular expression denial of service in OpenStack Swift allows remote attackers to interrupt proxy service via a crafted Accept header. The listing_formats middleware applies the qdtext pattern to an unterminated quoted value, and overlapping repeatable alternatives for backslashes trigger catastrophic backtracking in a proxy worker. Authentication is not required because the header is parsed before authentication; repeated requests consume the worker pool and make object storage unavailable.

The record

CVE
CVE-2026-71190
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
OpenStack
Product
Swift
Classifications
CWE-1333, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.9.1 <2.35.4
  2. Affected versionversion=2.36.0 <2.36.3
  3. Affected versionversion=2.37.0 <2.37.3
  4. Affected versionversion=2.38.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenStack · Swiftversion=1.9.1 <2.35.4; version=2.36.0 <2.36.3; version=2.37.0 <2.37.3; version=2.38.0

Published CVSS scores

7.5Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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