---
id: CVE-2026-86320
title: >-
  A flaw was found in flatpak-builder where Git hooks are not disabled when
  applying patch sources with use-git-am: true
summary: >-
  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…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-94
vendor: Red Hat
product: flatpak-builder
affected:
  - flatpak-builder (all versions)
  - flatpak-builder (all versions)
  - flatpak-builder (all versions)
published: '2026-09-17'
updated: '2026-10-12'
sourceUpdated: '2026-10-12T21:17:23.107'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86320'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:80495'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:80496'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:80973'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-86320'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2471023'
    label: secalert@redhat.com
  - url: >-
      https://github.com/flatpak/flatpak-builder/security/advisories/GHSA-j5p8-jgjc-f3xv
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2471023'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://github.com/flatpak/flatpak-builder/security/advisories/GHSA-j5p8-jgjc-f3xv
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-86320.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-86320'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86320'
  - url: 'https://access.redhat.com/errata/RHSA-2026:84834'
  - url: 'https://access.redhat.com/errata/RHSA-2026:84832'
    label: 'RHSA-2026:84832'
  - url: 'https://access.redhat.com/errata/RHSA-2026:84833'
    label: 'RHSA-2026:84833'
  - url: 'https://access.redhat.com/errata/RHSA-2026:84842'
    label: 'RHSA-2026:84842'
  - url: 'https://access.redhat.com/errata/RHSA-2026:86714'
    label: 'RHSA-2026:86714'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
epss: 0.00288
epssPercentile: 0.21215
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-17T15:42:59.014535Z'
ingestedAt: '2026-09-17T08:14:19.086Z'
patched:
  - enterprise_linux_appstream_eus_v_10_0
  - enterprise_linux_appstream_v_10
  - enterprise_linux_appstream_v_8
  - enterprise_linux_appstream_v_9
---

## Overview

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.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-86320.json)
- **RHSA-2026:84834** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:84834)
- **RHSA-2026:80495** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:80495)
- **RHSA-2026:80973** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:80973)
- **RHSA-2026:80496** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:80496)
- **RHSA-2026:86714** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:86714)
- **RHSA-2026:84842** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:84842)
- **RHSA-2026:84832** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:84832)
- **RHSA-2026:84833** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:84833)