Cyber Resilience

CVE-2026-34079

Path Traversal in Flatpak ≤ 1.16.4

Published
07 April 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0032 25th percentile
Risk Priority 44 floored blend · peak EPSS

Summary

CVE-2026-34079 is a high-severity Path Traversal (CWE-22) vulnerability in Flatpak Flatpak. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 25th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-34079 is a path traversal vulnerability (CWE-22) in Flatpak, a Linux application sandboxing and distribution framework. Versions prior to 1.16.4 contain a flaw in the ld.so caching mechanism, where outdated cache files are removed without properly verifying that the application-controlled path resides within the designated cache directory. This defect enables Flatpak applications to delete arbitrary files on the host system, earning a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).

The vulnerability can be exploited by any attacker who can convince a user to install and run a malicious Flatpak application, requiring no special privileges or user interaction beyond execution. Successful exploitation grants the ability to delete any file on the host filesystem outside the sandbox, potentially disrupting system operations, corrupting data, or facilitating further attacks such as persistence or lateral movement.

The official advisory from the Flatpak GitHub security page (GHSA-p29x-r292-46pp) confirms the issue and states that it is fully resolved in Flatpak version 1.16.4, recommending immediate upgrades for all affected installations to mitigate the risk.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Flatpak is a Linux application sandboxing and distribution framework. Prior to 1.16.4, the caching for ld.so removes outdated cache files without properly checking that the app controlled path to the outdated cache is in the cache directory. This allows Flatpak…

more

apps to delete arbitrary files on the host. This vulnerability is fixed in 1.16.4.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-39977Same vendor: Flatpak
CVE-2025-21048Shared CWE-22
CVE-2026-23939Shared CWE-22
CVE-2024-7145Shared CWE-22
CVE-2023-42225Shared CWE-22
CVE-2024-33109Shared CWE-22
CVE-2023-35016Shared CWE-22
CVE-2025-10723Shared CWE-22
CVE-2023-1163Shared CWE-22
CVE-2024-43996Shared CWE-22

Affected Assets

flatpak
flatpak
≤ 1.16.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

Enforces the intended directory access authorizations that path traversal would otherwise bypass.

Input validation directly neutralizes special path elements before pathname construction occurs.

Least privilege reduces the impact of any unauthorized file access obtained via traversal.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-02 partial match
prevents

Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.

PR.AA-05 none match
prevents

PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development catches path traversal via static/dynamic analysis.

prevents

Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.

prevents

Application security requirements include rules for safe file handling and canonicalization.

prevents

Secure architecture principles require least-privilege file access and directory isolation.

prevents

Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.

mitigates

Information access restriction limits which files an application may read or write.

References