CVE-2026-59959
SAIL: WebP decoder division by zero through malformed animated canvas metadata
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to version 1.0.2, the built-in WebP decoder can crash during loader initialization when processing a malformed animated WebP file with inconsistent container or ANMF frame metadata. In sail_codec_load_init_v8_webp() in src/sail-codecs/webp/webp.c, WebPDemuxGetI with WEBP_FF_CANVAS_WIDTH can return a zero image_local->width, which is then used as a divisor when calculating bytes_per_pixel from the image row size. The division happens before frame decoding and before generic image skeleton validation in src/sail/sail_advanced.c, causing an arithmetic fault and process termination. Applications accepting untrusted WebP images can consequently suffer denial of service; builds must include the affected WebP codec. This issue is fixed in version 1.0.2.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
4.8
SAIL: WebP decoder division by zero through malformed animated canvas metadata
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to version 1.0.2, the built-in WebP decoder can crash during loader initialization when processing a malformed animated WebP file with inconsistent container or ANMF frame metadata. In sail_codec_load_init_v8_webp() in src/sail-codecs/webp/webp.c, WebPDemuxGetI with WEBP_FF_CANVAS_WIDTH can return a zero image_local->width, which is then used as a divisor when calculating bytes_per_pixel from the image row size. The division happens before frame decoding and before generic image skeleton validation in src/sail/sail_advanced.c, causing an arithmetic fault and process termination. Applications accepting untrusted WebP images can consequently suffer denial of service; builds must include the affected WebP codec. This issue is fixed in version 1.0.2.
- Record
CVE-2026-59959- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-369
- Updated
- 2026-11-02
EUVDEUVD-2026-112083
4.8
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to version 1.0.2, the built-in WebP decoder can crash during loader initialization when processing a malformed animated WebP file with inconsistent container or ANMF frame metadata. In sail_codec_load_init_v8_webp() in src/sail-codecs/webp/webp.c, WebPDemuxGetI with WEBP_FF_CANVAS_WIDTH can return a zero image_local->width, which is then used as a divisor when calculating bytes_per_pixel from the image row size. The division happens before frame decoding and before generic image skeleton validation in src/sail/sail_advanced.c, causing an arithmetic fault and process termination. Applications accepting untrusted WebP images can consequently suffer denial of service; builds must include the affected WebP codec. This issue is fixed in version 1.0.2.
- Record
EUVD-2026-112083- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
NVD
4.8
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to version 1.0.2, the built-in WebP decoder can crash during loader initialization when processing a malformed animated WebP file with inconsistent container or ANMF frame metadata. In sail_codec_load_init_v8_webp() in src/sail-codecs/webp/webp.c, WebPDemuxGetI with WEBP_FF_CANVAS_WIDTH can return a zero image_local->width, which is then used as a divisor when calculating bytes_per_pixel from the image row size. The division happens before frame decoding and before generic image skeleton validation in src/sail/sail_advanced.c, causing an arithmetic fault and process termination. Applications accepting untrusted WebP images can consequently suffer denial of service; builds must include the affected WebP codec. This issue is fixed in version 1.0.2.
- Record
CVE-2026-59959- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/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 - Weakness
- CWE-369
- Updated
- 2026-11-02
OSV
4.8
SAIL: WebP decoder division by zero through malformed animated canvas metadata
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to version 1.0.2, the built-in WebP decoder can crash during loader initialization when processing a malformed animated WebP file with inconsistent container or ANMF frame metadata. In sail_codec_load_init_v8_webp() in src/sail-codecs/webp/webp.c, WebPDemuxGetI with WEBP_FF_CANVAS_WIDTH can return a zero image_local->width, which is then used as a divisor when calculating bytes_per_pixel from the image row size. The division happens before frame decoding and before generic image skeleton validation in src/sail/sail_advanced.c, causing an arithmetic fault and process termination. Applications accepting untrusted WebP images can consequently suffer denial of service; builds must include the affected WebP codec. This issue is fixed in version 1.0.2.
- Record
CVE-2026-59959- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-369
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-59959
4.8
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to version 1.0.2, the built-in WebP decoder can crash during loader initialization when processing a malformed animated WebP file with inconsistent container or ANMF frame metadata. In sail_codec_load_init_v8_webp() in src/sail-codecs/webp/webp.c, WebPDemuxGetI with WEBP_FF_CANVAS_WIDTH can return a zero image_local->width, which is then used as a divisor when calculating bytes_per_pixel from the image row size. The division happens before frame decoding and before generic image skeleton validation in src/sail/sail_advanced.c, causing an arithmetic fault and process termination. Applications accepting untrusted WebP images can consequently suffer denial of service; builds must include the affected WebP codec. This issue is fixed in version 1.0.2.
- Record
DEBIAN-CVE-2026-59959- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/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 - Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-59959 is a medium vulnerability (CVSS 4.8) in Happyseafox Sail, published October 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.12%, the 2nd percentile. Fixed in sail 1.2.0-1.
References
github.com/HappySeaFox/sail/security/advisories/GHSA-5g8g-g347-84m8
github.com/HappySeaFox/sail/commit/495660135a4c62e416a1b357a4381dd30069229d
github.com/HappySeaFox/sail/tree/v1.0.2
github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59959.json
nvd.nist.gov/vuln/detail/CVE-2026-59959
security-tracker.debian.org/tracker/CVE-2026-59959