CVE-2026-86320Public exploitHinoki check available

Host code execution via unsuppressed Git hooks

Published Sep 17, 2026 · Updated Oct 12, 2026

Code injection in flatpak-builder 0.99.2 through 1.4.10 allows attackers to execute host code via malicious build sources. Patch-source processing invokes git am without disabling hooks, executing an attacker-supplied post-applypatch hook outside the build sandbox. On Red Hat Enterprise Linux 8, 9, and 10, exposure requires untrusted sources and use-git-am: true; execution inherits the build user's privileges.

CVSS severity7.8
High
EPSS probability0.22%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Code injection in flatpak-builder 0.99.2 through 1.4.10 allows attackers to execute host code via malicious build sources. Patch-source processing invokes git am without disabling hooks, executing an attacker-supplied post-applypatch hook outside the build sandbox. On Red Hat Enterprise Linux 8, 9, and 10, exposure requires untrusted sources and use-git-am: true; execution inherits the build user's privileges.

The record

CVE
CVE-2026-86320
Published
Sep 17, 2026
Updated
Oct 12, 2026
Vendor
libuser Project
Product
Red Hat Enterprise Linux 9
Classifications
CWE-829, CWE-94, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

libuser Project · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.
libuser Project · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
libuser Project · Red Hat Enterprise Linux 10Affected versions are unavailable in this record.

Published CVSS scores

7.8Red HatCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-829Inclusion of Functionality from Untrusted Control Sphere
CWE-94Improper Control of Generation of Code ('Code Injection')
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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