CVE-2026-96280: flatpak Numeric Truncation Error
Vulnerability summary
CVE-2026-96280 is a high (CVSS 7.5) Numeric Truncation Error vulnerability in flatpak. EPSS estimates a 0.66% chance of exploitation in the next 30 days, higher than 51.1% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 3Timeline
- 27-09-2026PublishedVulnerability first disclosed.
- 12-10-2026Last modifiedVulnerability information updated.
Description
The OCI delta stream parser read sizes as guint64 but passed them to GLib I/O and allocation functions expecting gsize (32 bits on 32-bit systems), causing undersized allocations while subsequent operations use the original 64-bit size, leading to heap buffer overflows. An attacker controlling an OCI registry can craft a delta stream that triggers this during flatpak install/update, potentially achieving code execution on 32-bit systems.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.66%
Chance of exploitation in the next 30 days
Percentile
51%
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
