synced 14 MIN AGO
01 Record

CVE-2026-96807

In Flatpak before 1.18.1, a malicious sandboxed app can replace ~/.var/app/$appid/.ld.so with a symlink, causing regenerate_ld_cache to write files at an arbitrary location. The filenames and content

MediumPUBLISHEDCNA: mitre
CNA base score4.0 CVSS v3.xCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

02 Description

In Flatpak before 1.18.1, a malicious sandboxed app can replace ~/.var/app/$appid/.ld.so with a symlink, causing regenerate_ld_cache to write files at an arbitrary location. The filenames and content

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.11% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 1.7% of scored records. A rank, not a probability.
NVD base score
4.0 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
NVD analysis status
Awaiting Analysis. NVD last modified this record on 2026-09-26.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-09-23 16:54Z1 MO AGO
Last updated
2026-09-26 22:51Z1 MO AGO
Reserved
2026-09-23
Assigning CNA
mitre
Record state
PUBLISHED
Severity
Medium (CVSS 4.0)
CNA CVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
Weaknesses
  • CWE-61UNIX Symbolic Link (Symlink) FollowingCompound
  • CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')Base
Data version
5.2
Document digest
a9bf307d274815b037d9704d0248901a6cb46d849cb98ef9f72d146df2b061c8

05 Affected products

VendorProductVersionsPlatforms
FlatpakFlatpak0 to < 1.18.1Linux

06 References

07 Remediation

The issue has been fixed in version 1.18.1 by commits: * e13dfed https://github.com/flatpak/flatpak/commit/e13dfeda330625d2fecc3a54672dfd4dc9c83a5c "common: Fix return value and typos in flatpak_switch_symlink_and_remove" * f6c8fb5 https://github.com/flatpak/flatpak/commit/f6c8fb5fdb3737e2f45068afe12c4bf1d808fd55 "common: Use fd-based operations in flatpak_switch_symlink_and_remove" * 76c9296 https://github.com/flatpak/flatpak/commit/76c9296b6780ca67f44cf67f0823f086d692a592 "run: Harden regenerate_ld_cache against symlink attacks" For LTS operating system distributions, backports of these changes are available in the flatpak-1.16.x branch. Please note that cherry-picked libglnx changes "chase: Add internal glnx_chaseat_full for a strategic callback" and "chase: Add glnx_chase_and_mkdirat" are also required.

08 Fixed in

Debian 12

  • flatpak
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • flatpak
    Fixed in 1.16.6-1~deb13u2

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • flatpak
    Fixed in 1.18.1-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • flatpak
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 18.04 LTS

  • flatpak
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 20.04 LTS

  • flatpak
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 22.04 LTS

  • flatpak
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 24.04 LTS

  • flatpak
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.