High severity · published Oct 22, 2026
CVE-2026-115374
Incus 7.0.0 before 7.0.2 and 7.1.0 before 7.5.0 Unsigned Header Bypass in Presigned S3 Upload URLs
New
7.1
CVSS
0.2%
EPSS
No
On KEV
Description
Incus 7.0.0 before 7.0.2 and 7.1.0 before 7.5.0 contains a signature verification flaw in its built-in S3 server that allows presigned URL holders to inject unsigned x-amz-* headers. Attackers can add an unsigned X-Amz-Copy-Source header to a presigned upload URL to copy other bucket objects onto the granted key, disclosing their contents and ETags.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
IN
incus · lxc
7.0.0 before 7.0.2; 7.1.0 before 7.5.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-115374
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-115374
github.com
https://github.com/lxc/incus/security/advisories/GHSA-mmj7-8rgf-mx2h
www.vulncheck.com
https://www.vulncheck.com/advisories/incus-7.0.0-before-7.0.2-and-7.1.0-before-7.5.0-unsigned-header-bypass-in-presigned-s3-upload-urls
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