CVE-2026-40493
SAIL has heap buffer overflow in PSD decoder — bpp mismatch in LAB 16-bit mode
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, the PSD codec computes bytes-per-pixel (bpp) from raw header fields channels * depth, but the pixel buffer is allocated based on the resolved pixel format. For LAB mode with channels=3, depth=16, bpp = (3*16+7)/8 = 6, but the format BPP40_CIE_LAB allocates only 5 bytes per pixel. Every pixel write overshoots, causing a deterministic heap buffer overflow on every row. Commit c930284445ea3ff94451ccd7a57c999eca3bc979 contains a patch.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.8
SAIL has heap buffer overflow in PSD decoder — bpp mismatch in LAB 16-bit mode
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, the PSD codec computes bytes-per-pixel (bpp) from raw header fields channels * depth, but the pixel buffer is allocated based on the resolved pixel format. For LAB mode with channels=3, depth=16, bpp = (3*16+7)/8 = 6, but the format BPP40_CIE_LAB allocates only 5 bytes per pixel. Every pixel write overshoots, causing a deterministic heap buffer overflow on every row. Commit c930284445ea3ff94451ccd7a57c999eca3bc979 contains a patch.
- Record
CVE-2026-40493- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2026-23646
9.8
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, the PSD codec computes bytes-per-pixel (bpp) from raw header fields channels * depth, but the pixel buffer is allocated based on the resolved pixel format. For LAB mode with channels=3, depth=16, bpp = (3*16+7)/8 = 6, but the format BPP40_CIE_LAB allocates only 5 bytes per pixel. Every pixel write overshoots, causing a deterministic heap buffer overflow on every row. Commit c930284445ea3ff94451ccd7a57c999eca3bc979 contains a patch.
- Record
EUVD-2026-23646- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
9.8
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, the PSD codec computes bytes-per-pixel (bpp) from raw header fields channels * depth, but the pixel buffer is allocated based on the resolved pixel format. For LAB mode with channels=3, depth=16, bpp = (3*16+7)/8 = 6, but the format BPP40_CIE_LAB allocates only 5 bytes per pixel. Every pixel write overshoots, causing a deterministic heap buffer overflow on every row. Commit c930284445ea3ff94451ccd7a57c999eca3bc979 contains a patch.
- Record
CVE-2026-40493- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
9.8
SAIL has heap buffer overflow in PSD decoder — bpp mismatch in LAB 16-bit mode
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, the PSD codec computes bytes-per-pixel (bpp) from raw header fields channels * depth, but the pixel buffer is allocated based on the resolved pixel format. For LAB mode with channels=3, depth=16, bpp = (3*16+7)/8 = 6, but the format BPP40_CIE_LAB allocates only 5 bytes per pixel. Every pixel write overshoots, causing a deterministic heap buffer overflow on every row. Commit c930284445ea3ff94451ccd7a57c999eca3bc979 contains a patch.
- Record
CVE-2026-40493- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-40493
9.8
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, the PSD codec computes bytes-per-pixel (bpp) from raw header fields channels * depth, but the pixel buffer is allocated based on the resolved pixel format. For LAB mode with channels=3, depth=16, bpp = (3*16+7)/8 = 6, but the format BPP40_CIE_LAB allocates only 5 bytes per pixel. Every pixel write overshoots, causing a deterministic heap buffer overflow on every row. Commit c930284445ea3ff94451ccd7a57c999eca3bc979 contains a patch.
- Record
DEBIAN-CVE-2026-40493- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-40493
9.8
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, the PSD codec computes bytes-per-pixel (bpp) from raw header fields channels * depth, but the pixel buffer is allocated based on the resolved pixel format. For LAB mode with channels=3, depth=16, bpp = (3*16+7)/8 = 6, but the format BPP40_CIE_LAB allocates only 5 bytes per pixel. Every pixel write overshoots, causing a deterministic heap buffer overflow on every row. Commit c930284445ea3ff94451ccd7a57c999eca3bc979 contains a patch.
- Record
UBUNTU-CVE-2026-40493- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
sailDebian:13 |
All versions, plus listed versions 0.9.10-10.9.10-20.9.10-30.9.8-10.9.8-1+deb13u10.9.9-11.2.0-1 |
None known |
sailDebian:14 |
before 0.9.10-2, plus listed versions 0.9.10-10.9.8-10.9.9-1 |
0.9.10-2 |
sailUbuntu:24.04:LTS |
All versions, plus listed versions 0.9.0+repack-10.9.0+repack-20.9.0+repack-2.10.9.0+repack-2.1build1 |
None known |
sailUbuntu:25.10 |
All versions, plus listed versions 0.9.7-1build10.9.8-10.9.9-1 |
None known |
sailUbuntu:26.10 |
All versions, plus listed versions 0.9.10-10.9.10-3 |
None known |
sailUbuntu:26.04:LTS |
All versions, plus listed versions 0.9.9-10.9.10-1 |
None known |
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-2026-40493 is a critical vulnerability (CVSS 9.8) in Happyseafox Sail, published April 18, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 30th percentile. Fixed in sail 0.9.10-2.
References
github.com/HappySeaFox/sail/security/advisories/GHSA-rcqx-gc76-r9mv
github.com/HappySeaFox/sail/commit/c930284445ea3ff94451ccd7a57c999eca3bc979
github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40493.json
nvd.nist.gov/vuln/detail/CVE-2026-40493
security-tracker.debian.org/tracker/CVE-2026-40493
ubuntu.com/security/CVE-2026-40493
cve.org/CVERecord?id=CVE-2026-40493