CVE-2026-96281: flatpak Improper Access Control
Vulnerability summary
CVE-2026-96281 is a medium (CVSS 6.2) Improper Access Control vulnerability in flatpak. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6.3% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 27-09-2026PublishedVulnerability first disclosed.
- 30-09-2026Last modifiedVulnerability information updated.
Description
On a multi-user system, a user with an active local login session could downgrade a system-wide Flatpak app to an older version by removing the app's remote ref via the unprivileged system-helper RemoveLocalRef method, causing the anti-downgrade check to fail to find a reference date. A malicious local user could use this to expose other users of the same system to an app version with unfixed vulnerabilities.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated6.2MediumCVSS:3.1/AV:P/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated6.2MediumCVSS:3.1/AV:P/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
- NVDNIST6.2MediumCVSS:3.1/AV:P/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.17%
Chance of exploitation in the next 30 days
Percentile
6%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- flatpakAll versions (No fix recorded) | < 1.16.6-1~deb13u2 | < 1.18.1-1
Ubuntu1 product
- flatpakAll versions (No fix recorded)
2 vendors · 2 products
