Flatpak-builder: host code execution via `git am` hook execution in patch source extraction (`use-git-am`)
Summary
| CVE | CVE-2026-86320 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-17 08:17:02 UTC |
| Updated | 2026-09-18 19:06:08 UTC |
| Description | A flaw was found in flatpak-builder where Git hooks are not disabled when applying patch sources with use-git-am: true. An attacker who can provide a malicious source containing a Git post-applypatch hook can cause the hook to execute on the host during the build process, resulting in arbitrary code execution with the privileges of the user running flatpak-builder. |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.002180000 probability, percentile 0.125270000 (date 2026-09-21)
Problem Types: CWE-94 | CWE-94 Improper Control of Generation of Code ('Code Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.redhat.com/show_bug.cgi | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | bugzilla.redhat.com | |
| github.com/flatpak/flatpak-builder/security/advisories/GHSA-j5p8-jgjc-f3xv | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| access.redhat.com/security/cve/CVE-2026-86320 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank AISLE Research for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-05-11T20:27:44.000Z | Reported to Red Hat. |
| CNA | 2026-08-13T14:32:20.714Z | Made public. |
Workarounds
CNA: Avoid using use-git-am: true when processing untrusted manifests or source material. Where untrusted builds are required, perform builds inside disposable virtual machines or other isolated environments.
There are currently no legacy QID mappings associated with this CVE.