CVE-2026-71191
In OpenStack Swift through 2.38.0, S3API middleware does not enforce that semantic x-amz-* headers are covered by the SigV4 signature on presigned URL requests.
Overview
CVE-2026-71191 is a known-severity vulnerability. It was published on August 5, 2026.
Technical description
In OpenStack Swift through 2.38.0, S3API middleware does not enforce that semantic x-amz-* headers are covered by the SigV4 signature on presigned URL requests. An attacker who obtains a presigned PUT URL can inject an unsigned X-Amz-Copy-Source header, causing Swift to perform a server-side copy from an arbitrary source object using the signer's authorization context. The attacker can read any object the signer has access to, provided the target project_id, container name, and object name are known. This affects all deployments using the default s3_acl=false configuration.
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How CyberStrike helps
Reason, not just scan
It reasons through your app's logic the way a human pentester would, so it finds flaws signature scanners miss.
Learn moreVerified findings
Every finding is proven exploitable before you see it, which cuts the false positives that bury real risk.
Learn moreAI-driven DAST and SAST
Probe running apps and read source from one engine, so issues are caught before and after they ship.
Learn moreOpen source
Read exactly how it tests and what it reports. CyberStrike is open source and in early access.
View the repo
Frequently asked questions
What is CVE-2026-71191?
CVE-2026-71191 is a known-severity vulnerability. It was published on August 5, 2026.
How severe is CVE-2026-71191?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2026-71191?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-71191?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-71191 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.