7.1
HIGH CVSS 4.0
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
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.

INFO

Published Date :

Oct. 22, 2026, 7:17 p.m.

Last Modified :

Oct. 22, 2026, 7:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-115374 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linuxcontainers incus
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update Incus to a patched version to fix S3 signature verification flaw and prevent header injection.
  • Update Incus to version 7.0.2 or later.
  • Update Incus to version 7.5.0 or later.
  • Ensure S3 server configuration is secure.
  • Validate all incoming S3 requests.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-115374.

URL Resource
https://github.com/lxc/incus/security/advisories/GHSA-mmj7-8rgf-mx2h
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
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-115374 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-115374 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-115374 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-115374 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 22, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/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
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
    Added CWE CWE-347
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/115xxx/CVE-2026-115374.json">CVE-2026-115374</a>
    Added Reference https://github.com/lxc/incus/security/advisories/GHSA-mmj7-8rgf-mx2h
    Added Reference 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
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.