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Fencer Vulns
medium 6.0

CVE-2026-71191 json

In OpenStack Swift through 2.38.0, S3API middleware does not enforce that semantic x-amz-* headers are covered by the SigV4 signature on pr…

published 2026-08-05 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-53049

cvss
6.0
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

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.

Patch / fix

  • OpenStack Swift 2.35.4, 2.36.3, 2.37.3
  • swift Debian 12 2.30.1-0+deb12u3
  • swift Debian 13 2.35.1-0+deb13u3
  • swift Debian 14 2.37.1-6

debian advisories DEBIAN-CVE-2026-71191

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-71191 updated cvss 8.2

openstack-swift: openstack-swift: S3API presigned URL unsigned header authorization bypass

  • Red Hat OpenStack Platform 13 (Queens) rhosp13/openstack-swift-base, rhosp13/openstack-swift-object, rhosp13/openstack-swift-account, rhosp13/openstack-swift-container, rhosp13/openstack-swift-proxy-server
    affected: workaround, no fix planned “Will not fix”
  • Red Hat OpenStack Platform 16.2 python3-swift, openstack-swift, openstack-swift-proxy, openstack-swift-object, openstack-swift-account, openstack-swift-container, +5 more Red Hat OpenStack Platform 17.1 python3-swift, openstack-swift, openstack-swift-proxy, openstack-swift-object, openstack-swift-account, openstack-swift-container, +5 more Red Hat OpenStack Platform 18.0 openstack-swift, rhoso/openstack-swift-base-rhel9, rhoso/openstack-swift-object-rhel9, rhoso/openstack-swift-account-rhel9, rhoso/openstack-swift-container-rhel9, rhoso/openstack-swift-proxy-server-rhel9
    affected: workaround, no fix available

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA 4.0 6.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • OpenStack Swift

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.