Is CVE-2026-59959 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-59959 being exploited in the wild.

How severe is CVE-2026-59959?

Informational severity, published 28 October 2026.

Which products and versions are affected?

HappySeaFox SAIL prior to 1.0.2.

Is there a fix for CVE-2026-59959?

Yes: fixed in 1.0.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-59959 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-59959?

Check whether you run HappySeaFox SAIL at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-59959: SAIL WebP decoder divide-by-zero in canvas metadata handling

CVE-2026-59959 · Severity: info · Published 2026-10-28

SAIL is a cross-platform library for loading and saving images with animation and metadata support. A malformed animated WebP file can crash SAIL during image loading when it reports a zero canvas width to the decoder, causing a division-by-zero fault that terminates the process. Applications using SAIL to process untrusted WebP images are vulnerable to denial of service.

Technologies: HappySeaFox SAIL. Vendors: HappySeaFox.

Quick answers

Is CVE-2026-59959 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-59959 being exploited in the wild.
How severe is CVE-2026-59959?: Informational severity, published 28 October 2026.
Which products and versions are affected?: HappySeaFox SAIL prior to 1.0.2.
Is there a fix for CVE-2026-59959?: Yes: fixed in 1.0.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-59959 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-59959?: Check whether you run HappySeaFox SAIL at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 1.0.2

Technical details

The WebP decoder in sail_codec_load_init_v8_webp() retrieves canvas dimensions from the WebP demuxer and immediately divides bytes_per_line by image width to calculate bytes_per_pixel, without validating that width is non-zero. Malformed animated WebP files with inconsistent container metadata can cause WebPDemuxGetI to return zero for WEBP_FF_CANVAS_WIDTH, triggering arithmetic fault before generic skeleton validation occurs. An attacker supplying a crafted WebP file to an application that uses SAIL's WebP decoder can crash that application.

Affected products

HappySeaFox SAIL prior to 1.0.2

Timeline

2026-10-28: disclosed

References

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