---
id: CVE-2026-115374
title: >-
  Incus 7.0.0 before 7.0.2 and 7.1.0 before 7.5.0 Unsigned Header Bypass in
  Presigned S3 Upload URLs
summary: >-
  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…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-347
vendor: lxc
product: incus
affected:
  - incus >= 7.0.0 < 7.0.2
  - incus >= 7.1.0 < 7.5.0
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T19:13:43.999Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-115374'
references:
  - url: 'https://github.com/lxc/incus/security/advisories/GHSA-mmj7-8rgf-mx2h'
    label: GitHub Security Advisory (GHSA-mmj7-8rgf-mx2h)
  - url: >-
      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
    label: >-
      VulnCheck Advisory: Incus 7.0.0 before 7.0.2 and 7.1.0 before 7.5.0
      Unsigned Header Bypass in Presigned S3 Upload URLs
tags:
  - cve.org
ingestedAt: '2026-10-22T22:00:50.401Z'
---

## Overview

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.

## Affected

- `incus >= 7.0.0 < 7.0.2`
- `incus >= 7.1.0 < 7.5.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.