CVE 2026 96275

A malicious or compromised Flatpak repository can write attacker-controlled content to arbitrary locations on the host filesystem via extract_extra_data(). On system installs, the write happens as root. Two issues combine: files/extra is resolved via path operations that follow symlinks, and blob names from xa.extra-data-sources are not sanitized against .. traversal.

Red Hat has provided an estimated CVSS vector:

AV:N — payload is served from a malicious/compromised Flatpak repository over the network.

AC:L — both underlying bugs (symlink-following on the files checkout path, ../ traversal in the extra-data blob name) trigger reliably once the repo is malicious; no race condition or extra preconditions.

PR:N — the attacker needs no privileges on the victim host, only control of the repo content.

UI:R — a user/admin must add or trust the malicious remote and initiate an install/update from it.

S:U — kept unchanged since the vulnerable and impacted components (flatpak client/system-helper stack) already the same security authority for system-wide installs by design.

C:H/I:H/A:H — this is an arbitrary-file-write primitive; on system-wide installs it runs as root via the privileged system-helper, and an unconstrained root-owned write is treated as equivalent to full compromise.

Avoid installing Flatpak extensions from non-trusted sources.

Bugzilla 2539416 : flatpak: flatpak: Arbitrary write access as root via extra-data extraction

CWE-22 : Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Common Vulnerability Scoring System (CVSS) Score Details

Info alert: Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications ).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Understanding the Weakness (CWE)

Integrity,Confidentiality,Availability

Technical Impact: Execute Unauthorized Code or Commands

The attacker may be able to create or overwrite critical files that are used to execute code, such as programs or libraries.

Technical Impact: Modify Files or Directories

The attacker may be able to overwrite or create critical files, such as programs, libraries, or important data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, appending a new account at the end of a password file may allow an attacker to bypass authentication.

Technical Impact: Read Files or Directories

The attacker may be able read the contents of unexpected files and expose sensitive data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, by reading a password file, the attacker could conduct brute force password guessing attacks in order to break into an account on the system.

Technical Impact: DoS: Crash, Exit, or Restart

The attacker may be able to overwrite, delete, or corrupt unexpected critical files such as programs, libraries, or important data. This may prevent the product from working at all and in the case of protection mechanisms such as authentication, it has the potential to lock out product users.

Upstream acknowledges Sebastian Wick as the original reporter.

Frequently Asked Questions

"Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.

The term 'Affected' means that our Analysis team has determined that this product, such as Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to address this issue in the near future. This includes all minor releases of this product unless noted otherwise in the Statement text.

Upgrade to a supported product version that includes a fix for this vulnerability (recommended).

Apply a mitigation (if one exists).

Customers with the Technical Account Manager (TAM) RHEL Security Select Add-on can review this CVE directly with their TAM.

Apply a mitigation (if one exists).

Red Hat Engineering focuses on addressing high-priority issues based on the impact and product lifecycle expectations. Therefore, lower-priority issues will not receive immediate fixes.

Customers with the technical account manager (TAM) RHEL Security Select Add-on can review this CVE directly with their TAM.

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