CVE-2026-91059

Published Oct 20, 2026 Modified Oct 20, 2026 CWE-125

Description

The 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.

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Weakness Type (CWE)

CWE-125 Out-of-bounds Read

References

Frequently Asked Questions

What is CVE-2026-91059? +
The 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.
How do I check if I'm vulnerable to CVE-2026-91059? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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