CVE-2026-91059
MEDIUM 6.8The GUIX JPEG software decoder enforces no ordering on JPEG markers. A file that places a second `SOF0` frame header after `SOS` re-runs the frame header parser after the output buffer has already been allocated and its geometry latched. The decoder returns `GX_SUCCESS` and publishes a `GX_PIXELMAP` whose reported dimensions and `data_size` exceed the allocation behind it. Any consumer that trusts the returned structure reads out of bounds, including GUIX's own display drivers, reached through the ordinary draw path. Reproduces in the shipped default configuration; `GX_SOFTWARE_DECODER_SUPPORT` is enabled by default.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
—EPSS not yet scored
Impact if exploited
6.8CVSS 4.0 · MEDIUM
- ConfidentialityHigh
- IntegrityNone
- AvailabilityLow
What an attacker needs
- ⚠Access: Requires local access to the host
- ✓Privileges: No account or privileges required
- ⚠User interaction: Requires active user interaction
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-91059/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-91059/poc.json
Weakness (CWE)
- CWE-125: Out-of-bounds Read
CVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N
All CVSS metrics
- MEDIUM 6.8 v4.0 · CNA Primary
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N - MEDIUM 6.8 v4.0 · NVD Secondary
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:L/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